I was a grad student at MIT, when Viki Weisskopf was still a professor, though elderly.
He was invariably a gentleman, at least as far as I could observe.
An example:
Physics department colloquia were held in 26-100, a huge lecture hall, in those days. All the senior profs, particularly theorists, sat down front, stage left.
One day a visiting physicist giving the colloquium apologized for being so elementary, reminding us all of the basics of.... something or other.
Viki stood up and *interrupted*, something he *never* did. In his lovely Mittel-Europe accent, he shook his finger and grinned, saying: "Young man, you should never underestimate the pleasure of a physicist at being told something he already knows!"
Then he sat down, there was applause, and the talk went happily on from there.