The gist appears to be that a colleague put a hand on his shoulder to get his attention and Mr. Gerber interpreted this as an assault. The court disagreed with his interpretation, as did the US 6th Circuit upon appeal.
The nature of the firing makes a lot more sense if this is an individual with a history of reacting to common workplace interactions with legal action.
I have a feeling his overall claim of being fired solely because of his opinions about diversity is about as valid as his claims of being assaulted.
[1] https://caselaw.findlaw.com/court/us-6th-circuit/1871365.htm...