Yeah, they weren't really advancing anymore, so pw had to give them something supernatural to keep things moving. Probably so this one mission doesn't hold up all the others.
Theoretically he could pull a mission failed due to running out of time..
Maybe they've already failed and he's just waiting to see how badly they've failed. That could be the case if, for example, the other building was UWM controlled and the UWM operatives inside know about the data there. So they go there, open the security deposit box and it's empty or has a bomb in it.
It would be very funny though if the UWM had the same method of extracting the data: robbing the bank. So our guys go in, start stealthily incapacitating guards, when suddenly, there's an explosion on the other side of the bank and some unknown guys in high tech gear start blowing things up, beating civilians to death and being all HMRC-like as they try to reach the safety deposit box. It would be a fun inversion. Now our guys are competent but few and under-equipped and their guys are suddenly numerous, incompetent and armed to the teeth.
EDIT: Or maybe it was a trap all along, meant to lure them in and by waiting so long the guys waiting to ambush them eventually got bored and left, leaving nothing there. Well, nothing except a lot of money. Our spec-ops team needs a retirement fund for the one or two that manage to survive.
It's a shame M18 can't ask Skylar to use the magic computer to delete the Eater of Cold. Also, couldn't M16 just use the computer to teleport the contents of vault and deposit boxes to a warehouse or something, then take what they needed along with extra stuff, and leave?
You see, the reality bender seems to require wireless/radio connection first and something programmable. It electronics, circuits and such it can handle, but like pw said; brick doesn't have any code for you to modify. Can't teleport things out.
Ah, but here's a thing: if it can delete, then why not create? I'm a bit surprised nobody thought of that.