Here is an examination done by Lord of Admirals to provide more understanding of Caption Del Rio as a Character and his actions.
Andrew Del Rio’s placement as Captain of the UNSC was not one fueled by skill or integrity, but rather fueled by politics and forgetability. The UNSC Infinity was not an easily concealed project. When it began construction on 2537, it took up half the UNSC’s budget and required a Captain and construction force who could easily drop off the grid. Del Rio turned out to be the perfect choice. While he was a competent leader and Captain, his particular way of handling navy battles allowed him to disappear relatively unnoticed.
It’s not easy to find a competent commanders who can drop off the grid unnoticed for that long. -BB referring to Del Rio, Page 422, Glasslands
Despite the fact ONI had commissioned Infinity, Del Rio was not ONI’s choice as Captain. With the prototype ship taking up such a large chunk of the budget, the UNSC found out about the project rather easily. Not wanting ONI to dominate the project and to secure Infinity’s safety, they chose Andrew Del Rio, while ONI opted for Thomas Lasky.
Unfortunately, the Wooden top Navy needed to know about her because even ONI couldn’t hide anything that big in the budget, but it’s still known to only a handful of very senior officers. -BB to Osman, Page 421, Glasslands
ONI would eventually concede from this battle, deciding it’d be better to share the ship. However, Del Rio would eventually prove to not be an adequate Captain of Infinity. He was no leader that people would die for, nor was he inspirational. He was simply a manager.
Del Rio wasn’t her choice of captain for Infinity. She’d learned to pick her battles and had conceded to that one, but she felt vindicated by observing his crew’s body language. He was just someone filling the uniform, a manager rather than a leader. -Parangosky contemplating Del Rio as Captain, Page 48, Thursday War
Nevertheless, Del Rio handled Infinity fine in the years that followed. He would soon learn Infinity’s awesome power in the year 2553. During that time, the Sangheili Civil War was just beginning to heat up, and it threatened the Arbiter, the UNSC’s only Sangheili ally. This prompted Infinity to be sent on a Thursday War to Sanhelios as both an impromptu test, and defense of an ally. This Thursday War would show Del Rio just how powerful Infinity is as it was capable of shooting down multiple ships and outright halt the Sangheili Civil War.
Good work, Austin.” Del Rio managed a smile. “I think I am going to like this ship. -Del Rio after shooting down Defender of Faith, Page 303, Thursday War
After Infinity was officially recommissioned as a ship designed for peace, it would be tasked with locating the remaining Halos and study them for decommission. This task would lead to the discovery of the Composer on Installation 03, and subsequently lead Infinity to Requiem in the summer of 2557.
Once the Didact had tricked Master Chief into releasing him, he immediately downed Infinity on Requiem, taking away power and control from the ship.
“Mayday! Mayday! This is the captain of the UNSC Infinity. Unknown enemy has seized control of our ship. We’re without power, and on a collision course with an unidentified Forerunner planet!” -Cutscene, Forerunner, Halo 4
And despite the fact Infinity was being forced to crash on Requiem, Del Rio still assumed from his prior experiences that Infinity could handle its current predicament. So he sent out Pelican recon teams to locate the source of the gravimetric disturbance.
“You were sent on a scouting run in the middle of an attack on the ship.” “The Captain thought Infinity could provide us cover and hold off the attack at the same time.” -Cutscene, Infinity, Halo 4
Infinity would be thrust into a situation it could not handle. All Pelican recon teams would be shot down along with the invasion of Infinity by Promethean and Covenant forces.
Infinity, this is Cmdr. Lasky. Pelican recon teams are down. Repeat. All birds are down. We’ve got numerous casualties and require immediate assistance. Over. Finally… Did you get the coordinates for that gravity well? Affirmative, sir. But we’re going to need a bus out of here— “Make it happen— -Cutscene, Infinity, Halo 4
Infinity’s bridge would be breached minutes later, prompting Del Rio to order all UNSC forces to return to Infinity to repel the invaders in an attempt to save the ship.
Mayday, Mayday, Code Red. Hostile elements attempting to gain entrance to Infinity bridge! They’re outside the hatch! Doors breached! Doors breached! All units return to Infinity immediately! That’s an order! -Gameplay, Infinity, Halo 4
As UNSC forces began to take back Infinity, Master Chief would be sent by Del Rio to reactivate Infinity’s ship-wide defense network in order to break the Didact’s connection with Infinity’s mainframe and disable the nearby CRS-Class Light Cruisers.
That satellite took down the ship’s defenses and is extracting data from the mainframe as we speak. -Gameplay, Infinity, Halo 4
This close encounter with Infinity’s destruction shocked Del Rio. His prior experience with Forerunner technology had never resulted in such a hostile response. His way of handling ships also prompted him to make Infinity’s return to UNSC space a priority. His service record is decorated with numerous ships under his command surviving engagements with the Covenant in one piece. He had no intention of losing Infinity and costing Humanity their dominant role in the Orion Arm.
What I want to know, people, is: where the hell did those things come from? It’s possible that they’re native to Requiem… or whatever counts as native for a Forerunner AI. We’ve never seen this type of offensive reaction from any of the other installations. -Cutscene, Infinity, Halo 4 This is a first contact scenario, Master Chief. Priority is to free Infinity from Requiem’s gravity well and file a threat assessment back at FLEETCOM. -Cutscene, Infinity, Halo 4
Master Chief would of course object to Del Rio’s plan to leave. But with Infinity’s Ship-Grade AI destroyed during the crash and the harassment the ship received, Del Rio would be put in a hard place. He saw no other option but to make a tactical retreat and return better prepared.
Sir, Infinity drove the Didact back. He’s vulnerable. He isn’t the only one. You know, I’d think you of all people would appreciate the benefit of living to fight another day.” -Cutscene, Infinity, Halo 4
Despite all of Infinity’s Pelican recon teams that were initially sent out being shot down, they did complete their objective of finding the source of the gravimetric disturbance that forced Infinity onto Requiem. With the Gravity Well keeping Infinity on Requiem, Del Rio made it their next objective to disable the Gravity Well so Infinity could leave. Not wanting to subject Infinity to any more time on Requiem than necessary, he chose to not send in recon.
Captain, what’s Force Recon’s assessment of the terrain? I know you’ve been off the field for awhile Master Chief, but this is a blowthrough op. Sending in recon would slow us down. Telemetry indicates the particle cannons are being controlled from a command post southwest of our position. Roll on that target and neutralize those guns. We’ll meet on the other side and take the gravity well. Infinity out. -Cutscene, Reclaimer, Halo 4
As the ground teams sent in began to take out the particle cannons blocking the air corridor to the Gravity Well were taken out, Infinity would move up in an attempt to neutralize the Well. That would prove to be more difficult as the sheer amount of Covenant air traffic would swarm and engage Infinity, giving it a beating and preventing a target lock.
We’re taking a beating up here. “Does Infinity have a shot on the gravity well? Negative. We’ll never be able to get a target lock with all the air traffic we’re seeing. -Gameplay, Reclaimer, Halo 4
Master Chief would give Infinity that target lock, resulting in a missile from Infinity collapsing the Gravity Well. Once the UNSC forces were back aboard Infinity, Master Chief would once again argue for a continued campaign on Requiem in order to defeat the Didact, claiming that an encounter he had with Forerunner technology revealed history shattering revelations. Humanity had once been a space-faring civilization capable of rivaling the Forerunner Ecumene.
Ancient Humanity would be battered by the Flood, crushed by the Forerunners, and devolved and composed by the Didact. Del Rio would find difficulty in believing such ludicrous claims resulting from an intelligence on a on a seemingly, entirely hostile Forerunner world. Despite Master Chief’s persistence, Captain Del Rio would order Infinity’s return to UNSC space.
Infinity can not handle that kind of punishment, not again! This isn’t about us or the ship anymore. Sir, we’ve seen what the Didact is capable of. If we let him leave this world, Humanity will be at risk.Look, I understand what you think you saw— -Cutscene, Reclaimer, Halo 4 Nav — As soon as we know we’re airtight, I want a course laid into Carinae Station. Comm, prepare a warning beacon.” -Cutscene, Reclaimer, Halo 4
The order to return to UNSC space would push Cortana over the edge and reveal just how badly she had deteriorated due to Rampancy. Not wanting to endanger Infinity and it’s crew from a potentially life-threatening rampant AI, Del Rio ordered her termination.
I WILL NOT ALLOW YOU TO LEAVE THIS PLANET. -Cutscene, Reclaimer, Halo 4 “Commander Lasky. Pursuant to Article 55 of UNSC Regulation 12-145-72, I am ordering you remove that AI’s data chip and retire it for final dispensation. -Cutscene, Reclaimer, halo 4
This event would reveal where Master Chief stood. He would take possession of Cortana’s chip, and keep it aboard Infinity; an act that could endanger the crew. Having undermined Del Rio’s authority, the Captain’s reaction was intense. As a manager rather than a leader, he would be unable to handle the situation correctly, and ordered Master Chief’s arrest.
Lieutenant. Arrest that man! Captain… ARREST HIM!!! CAPTAIN! -Cutscene, Reclaimer, Halo 4
But it was too late. Master Chief, being Humanity’s living legend and savior, had inspired Infinity’s crew by his unflinching resolve to meet the Didact’s thread head on. No one would attempt to arrest him.
As word spread of what had happened on Infinity’s bridge, and it became apparent that Del Rio would abandon Chief, the crew would speculate what Del Rio’s fate would be and mull over what had happened.
Ah-ha! The old man tried tearing him a new one. Good luck with that. And good luck on the night watch, private. The old man is still your commanding officer and you will refer to him as such. Are we clear? “Sir, yes sir.” -Gameplay, Shutdown, Halo 4
Look, I fought to get this assignment, I’m just saying—“The chain of command is still chain of command. C’mon, who do you think FLEETCOM is going to side with? Don’t be naive. -Gameplay, Shutdown, Halo 4
As Infinity returned to UNSC space, its final destination would be Cairo Station, where Del Rio was presumably debriefed. A peaceful exploratory mission would lead to Infinity’s near destruction, the discovery of a new world, new enemies, and the survival of the Master Chief. Del Rio’s choice to not take the initiative would ultimately cost him his position and the loss of physical form and free will for millions of Humans.
Affirmative, Sir. Where’s the Captain? FLEETCOM didn’t take to kindly to his abandoning you on Requiem. I’m afraid I’ll have to do. -Gameplay, Midnight, Halo 4
Del Rio’s final fate is still unknown, but we speculate that he was given command of another ship, or demoted and stationed elsewhere.