Desperately seeing an Ocean’s 11 answer

Ocean’s 11 aficionados, I have a question that I desperately want answered.

Here’s the scene:

Danny and Linus have knocked out the guards outside the vault with a smoke grenade. They bang on the vault door. Yen is in the vault, and he bangs as well, indicating that he is ready to go. Yen applies a single explosive charge on his side of the vault and Danny applies a circle of charges on his side. There is a brief moment of tension when Yen’s bandaged hand gets stuck in the vault and the detonator in Danny’s hand thankfully fails due to dead batteries, but eventually the door is blown off off and everyone is safe.

Here is what I am missing:

There are floor sensors in the vault. This is the reason Yen has been hired in the first place. He can leap from the cash cart to the vault door because he is an acrobat. But when they blow open the vault door, wouldn’t these floor sensors fire off, indicating the intruders?

How could they not?

Right?

So what am I missing?

This has been bothering me a lot.

Not quite as much as the notion that an EMP would temporarily disable power to the Vegas strip (an EMP permanently destroys any electronic device that it operating at the time of the pulse is released), but it’s a close second.

The EMP annoys me because it could have been easily fixed. There are any number of amusing ways in which Basher could have knocked out power to the casinos, so why would the writers specifically choose exceptionally faulty science to get the job done?

But at least I know that this is a mistake.

I keep feeling like there is an explanation to the floor sensor issue.

Someone ease my mind and explain what I am missing. Please?