Yeah this is unacceptable behavior. That said I think this is something that ought to be just explained to him because he might legitimately be a total dumbass.

That said I wish more restaurants were like Fuddruckers or Firehouse Subs and just let me grab my food from the counter myself once it was done. I don’t really want to pay someone to carry my food & drinks to me and be possibly insincerely nice to me to increase their tip or whatever.