Only when I was working in a microbiology lab... and I am pretty sure the people who were actually microbiologists in that lab (I have degrees in biomedical science and immunology but not microbiology) did not spend their time tying each other up for course credit...

Wierd comment. You sure he didn't say something else and you misheard it because of background noise or something? Or maybe he mistook you for someone he knew who was a microbiologist?