Over his decade-long career as North Dakota's head coach, Hakstol has faced suspension. Specifically, a two-game suspension when he flipped off assistant ref C.J. Beaurline.
During a game between Hakstol's UND and the University of Minnesota, a dust up between players led to a Minnesota powerplay. Hakstol and Beaurline talked about it, and as Beaurline turned away, Hakstol flipped him off.
Beaurline didn't notice. TV cameras did. And thus, apologies, and suspensions.
Hakstol's reputation is more along the lines of not getting shaken up, so it was definitely an out of character move for him. Though there are worse things you can do to a ref, I suppose.