IS it normal to yell at customers?

I have nothing to gain from making a false review. I do understand how stressful it can be, I used to be a waiter. Still that is no excuse to lose your cool and I am not the first to complain about their attitude

Yep

I have been dining at the Nautilus for years. I know many of the staff and management and have seen them in various stressful situations. Never have I witnessed your alleged experience.