For our first OOP module in Python, we had a lecturer who's main language was Java. His slides were taken from a Java book with the code turned to Python, and he was learning the things he was teaching us the day before he taught us.

He would also code up his examples for the first time in class, without having practiced them beforehand. This led to him taking up the latter half of class looking confused at the code he wrote and trying to fix it, leaving us learn nothing. One time, when he was already 10 minutes over time, he said "if i had 5 more minutes, i could have fixed this" even though we all could see that wasn't going to happen...