Might be on a tight schedule and that's why they kill the wife and get out of there in a hurry. I wonder why the amazing Shaun is so special that they took him though.
[edit]
Remember how whatshisface plugs in his pipboy into some slot before he opens up the vault door? Maybe it has some kind of sensor module in it that allows him to use the button up top to get down. Like, it only activates if you have the right code in its sensor module. But that means Mr Cornflakes... Uh... Is... The head of Vault Tech. Obviously! See, it all makes sense guys! It just works.
So General Mills has a Pipboy of his own that can hack vault doors?
OK, fine. Whatever.
I'm still trying to figure out why he's there in the first place. Is the Institute supposed to be like the Master's army, scouring the vaults for people to turn into mutants... er, androids?