In the Bellagio vault, there were ground sensors, shown as green lasers. It's because of the that Glenn needs to jump around without being on the ground. However, the gang explodes the vault doors and it's as if the sensors just vanished.
Is this a plot hole? Or am I missing something?
This surely is one of the mistakes that the movie makers made. There is actually no way that the explosion at the door could have disabled the power supply (or even opened the door - as an engineer this bothers me every time I watch the movie). By the way, the reason the Chinese guy jumps is motion detectors, not the ground sensors. One could argue that the ground sensors only monitor the ground and not the inside of the vault (but why then are the motion sensors suddenly out of order when the door opens??) or you could argue that the ground sensors are for long term monitoring instead of being an alarm system.
But for an actual answer, its an mistake. Other mistakes are that there is no way the bags with the hooker flyers could have made their way into the vault or that Mr. Walsh is simultaneously watching the cameras with Liman Zerga and showing Frank the exit.
A con this complex is obviously too complex even to IMAGINE a way to do it
After explosion security of vault was compromised including ground sensors as they are part of vault and connected to doors. So ground sensors system was also damaged, simply like if you take fuse out of your house, nothing would work. This is my theory, it might have been good if they had short explanation of this in movie.
