He had no reason to expect him to put the sponge on dry and was not specifically checking for it. If he was distracted he might not have easily noticed.

Good catch, Jay. In another thread, someone claims that Paul did notice, but was loath to delay the proceedings.
When you think of garbage, think of Hakeem!
Folks, calm down! This is not the last chopper outta Saigon!

I disagree with this. Remember, in the movie, Percy had just said
"There is no Mouseville, you French-fried beep Burn in hell.
or something along those lines. Paul, Dean, Harry & Brutal were so shocked that they were distracted from the wetness of the sponge. They were seething at Percy! Completely distracted and that is why they didn't notice. So tremendously sad.

That had all done several executions
Is this specifically mentioned?
Hey! You're not old enough to drink! Now go and die for your country!!!

Simple, they are all just going through the motions. That had all done several executions and they just do their part as if it's no big deal.

I agree 100%. He should have lost his job for negligence. Especially for someone that had performed the act several times.
K/H D
If there's a way to screw something up, the "O'Commie regime" will find it EVERY SINGLE TIME!!