Yes, it was a "bad joke", and yes it was offensive to not only the students in question, but also to many in society.  Those that see his comments as a joke do not fully appreciate how offensive his comments were.  For the Globe and Mail to attempt to equate the use of the word master as skillful being the same as a slave owner is plain idiotic.  I am not offended by the title of Master for Massey College -- I am deeply offended by the use of the word master as a slave owner, as Marrus did.  This is essentially the same situation as the the fellow from Ontario who's name is Grabher, and who had his personal license plate cancelled because someone found it offensive.  There is a difference between "Grabher" and "Grab her", and Master and master.  Unfortunately for Prof. Marrus, he found humour in expressing a derogatory comment to a minority who he should have known would find it offensive, just as he would find any derogatory Jewish term aimed at him.  He should expect such responses.