Wow... It hasn't been all rainbows and unicorns with every auditor, but some of these examples are unprofessional enough that I would expect "consequences". The least mature auditor I encounter on a regular basis has a particular personality quirk that we accommodate despite it almost never being directly relevant to the area he is auditing... he always asks to see "the source code". I suspect he is a frustrated former programmer (of some variety) and feels like putting eyes on "source code" gives him some peculiar insights. Picture an amateur craftsman who just likes seeing what tools you have on hand. Once, this gentleman had eyes on a process where there was literally no source code, and he strongly pleaded that we should show him something like source code, no matter how tenuously connected to the process. He is an otherwise reasonable auditor, but on this topic I feel like he has conclusively proven himself to have a very peculiar hang-up.
The least professional "audit-like" experiences I've had have been with "fauxditors"... that is, people who thought they were auditing but had nothing like a plan to follow, and were incapable of explaining their methodology beyond "I'll know something is wrong when I see it." I have had more run-ins with folks like this than I care to recount. The most bitter example I have is from an experience where I was providing audit support by lining up the OE documents for the person having face-time with an auditor. My "fauxditor" was placed in the back room, and all that person did was to slow us down by demanding to see minutae about the projects under audit... along the lines of "I bet you didn't do ____, they'll get you!"... they were so bad that they got booted from the room.