Max Acceptable Deck slope?

I once worked for an employer, that had an open pit policy. The customer was allowed to watch, from a safe distance,(if there was such a thing). Many didn't observe the no-go zone.
I used to pull the Oops-card occasionally, if a customer was getting in my way.Just drop something heavy, and say,Oops. They usually back up some. Job's took longer, and the extra time went on his bill, but their curiosity was satisfied.I often had to repeatedly ask them not to come between me and my tool box. Many never seemed to catch on.
Talk, talk, talk,talk, oh how they loved to talk.