Hate to say it but one day someone is going to push somone in and the cops will be called in again. Didn't we learn anything from the "nipper tipping" nonsense.
Regardless of any racial overtones, if you push someone in, at the very least, it is battery. More likely you can be charged with assault. If he gets hurt, etc.... the consequences will become very severe indeed.
Unfortunately, the etiquette of fishing that some of us were raised on, has basically died. It has been replaced by the North American mentality of " anything goes until you get caught". It's not just fishing where you find this selfishness. It happens hunting, golfing, hiking the trails, on the sidewalk, and worst of all, our highways.