"Navigable waters" is a fluid definition - no pun intended. What the U.S. considers "navigable" was completely re-defined and contracted in the mid-90's by the Bush administration, and has not, to my knowledge, been expanded by the Obama administration. Lots of small rivers and streams lost the classification of navigable water, and could then be opened for exploitation (i.e. "damage beyond natural repair") by the extractive industries.
With all respect due, it shouldn't matter what an angler knows about any spot on any water. Waiting five or ten minutes - an hour or two - for others to finish is probably not going to be a fatal. Nor would it most likely be fatal to move along and let someone else fish behind you UNLESS you're into the fish, at which time I'd respect the first one there - but I'd aggravate the bejeebers out of them with pesky questions until they left. But I'd never shove in and fish on top of them.
In the front of the regs, there's a section on etiquette that talks about how we should all play in the sandbox. This was not how we shold play together and there's no excusing or justifying this behavior.
The guys on the bank had a we-were-here-first claim to that spot. The guy who came late should have had a seat and waited them out or moved-on.
troutmasta, you're a fine human being, but I don't want your - or anyone else's - body wastes in the water. The worst slapdown I ever received was in a seminar on Environmental Hydrology, where the presenter kept repeating: "The solution to pollution is dilution" - meaning "dump it into the boundless surface waters" of the planet - and I asked them, "What happens when we run out of water?" And we are running out of clean, fresh water. And sea water, for that matter. I honestly don't want someone to urinate where it might reach the water, untreated.
But perhaps the real problem wasn't all the fluids being sprayed around, perhaps it was that the gentleman didn't find a sufficiently private location to relieve the pressure? I mean, if he couldn't be seen taking a leak, no one would have raised a stink about it, would they?
Bear that in mind: keep it out of the waterways and find deep cover.
And BTW, when did the word "p**s" become more crass than "pee"? Maybe all of it should be changed to "urinate" as not to offend anyone in this family-oriented forum. JHCOAPS!