In my opinion it's not about "forced actions"!
The professor was angry because he thought the student acted like forgetting the first time jerking off together and went crazy after the BJ (he thought the student lied about forgetting the first time, because student took again actions first) Not consensual is not the topic here, but the student can't remember jerking off with the professor and searched for a reason why the professor was avoiding him and came ON HIS OWN to the conclusion that the prof maybe felt forced
--> it's a misunderstanding because they don't communicate.
PS: i read the comments and wanted to. share my thought (=・ω・=)