Stop in for a cup of coffee

Fair enough.
The question then is whether its worth a private lawsuit, or just report it to whomever is responsible for enforcement. Could be labor department or state AG or ? That way there's little time or money spent on Karl's part.
The physical assault would go thru local law enforcement but that’s a highly time sensitive matter. State AG would be one most likely. The other would be The DoL of his state. That’s where I’d call first. Without giving names or any thing, I’d inquire about the legality of being walked out after reporting a physical assault to HR.