If this happened to me, I'd be writing a letter to the company, with a copy to BLM, which regulates commercial outfitters on that stretch. Date, time, location, number of witnesses, name of guide or description, etc.
Most companies are not particularly interested in their staff getting into public confrontations -- it doesn't reflect well on their operation. And they know that BLM tracks problems that commercial outfitters have on its rivers, so the owners have an interest in keeping things calm and collected. It even could be that the guide in question has had other incidents, and knowing about this one could help them deal with a problem employee before something more concerning happens.
And if your camera was damaged by his action, I'd be asking them to stand for the cost of a replacement. You might not get it, but then again they might do the right thing by you. You never know...