Eh, let's not skip the important step of "if the million mics in the building actually confirm Prust's allegation".
I'm inclined to not believe Prust, mainly because he's a giant tool, but if shit went down like he said then the league will do something. But if this is a Darcy Tucker spitting incident (ie, a guy does something dumb on the ice, moments after the game while all goofed up on adrenaline gives a very exaggerated version of what happened in his defense) then it's going to be more than a fine for Prust.