As to his "offensive language", I had never heard the term or knew what it meant until your posting. I googled it to find out. So it is possible that he didn't know the term unless this is a common term known only to men.

In regards to his subsequent denials, he is probably in total CYA mode. He has probably learned his lesson about sending out emails assuming that everyone under the sun agrees with his thinking. I'd let it drop. It was a bad decision but that doesn't necessarily make him a bad person.

YMMV