Did the burglars from the beginning get away?

I think you are stubbornly overlooking nuances in the script and direction here. The driver is extremely competent, yes: but he also lays out very clear boundaries of what is and is not his responsibility. "Anything happens in that five minute window, I'm yours. No matter what. Anything happens a minute on either side of that, you're on your own. You understand?"

Now, this does not technically, literally apply to the point when they get to the arena. But the dynamic has been laid down. He will do his job to the utmost, and get them to a place where they have every chance of escaping if they act just as professionally and competently as he does. But they are "on their own" after he parks the car. It's not his problem. It's not his job to hold their hands at that point--he never looked back. And I just don't think they looked like they were up to the task. They were not as highly skilled as he is. That doesn't make HIM a Will Ferrell buffoon! That's on them.

And don't forget, one of the two masked burglars (or perhaps robbers: the police radio said "shots were fired") was very slow to exit the building they robbed. His partner was sitting there like "C'mon, c'mon, where are you man?!?" If that second guy had gotten out as quickly as the first one did, maybe they make a clean getaway right from the beginning and there's no real drama. The driver can just drop them off wherever they had originally agreed to (I've got to think the arena was an emergency backup plan for if things went pear-shaped).

The last point at which we see the two thieves is a shot of the back seat just as they've pulled into the parking ramp. They don't look steely-eyed, ready to spring into action. They look kind of freaked out and a bit confused about what's going on. Then when the driver parks, we can't see the back seat but it sure doesn't look like those back doors open at the same time he gets out. Then just a few seconds after he has walked away from the car, cop cars converge on the area where he parked. To me, it doesn't look promising for them but it's left ambiguous, which is a nice touch.

One more thing it occurred to me to add has to do with his reputation in the criminal underworld. Obviously it doesn't look great for the people he drives to get busted. But what story are other criminals going to hear? "The two dudes in the back seat got picked up by the cops, but the driver was in the wind." The proof is in the pudding: he got away clean, so they could have too--but once it was no longer about driving but about walking, they failed and he did not. Not his problem, not his fault.