Bar staff picking their noses while serving

As I looked up, I noticed a guy behind the bar scratching his nose. I notified my friend, and to my dismay saw a second person doing the exact same thing. I immediately told my friend that that was the second one I saw, even though he just saw it happened once. He told me that we shouldn't worry because we haven't been rude to our waiter and it's probably intended for someone that deserves it. I got my phone out to try and get them on camera, but we were caught spying. Immediately everyone disappeared from behind the bar and I felt all their eyes gazing from all over everytime I looked around. We didn't order any food and opted to take our glasses and watch them rinse it out and refill it. We asked for the bill, stared the waiter down and didn't give any tip. I really wish I could have been able to get them on camera. Until now, I cannot believe this kind of stuff really happens, and I know nothing will come of this