First off, if you understated the level of conflict like you understated the size of your elk this Dale must be one of this world’s all time jerks. Congrats on that elk.
If you don’t plan on going back to that spot ever again I would certainly pursue the incident to the fullest extent, especially given your credible witness and gps proof you never trespassed. Sounds like your position is pretty much bulletproof, and by that I mean you sound like you have enough support for the appropriate authorities to take action so you wouldn’t be wasting your time.
Think about this as well, what if a fellow hunter and say his/her young kid were taking a rare or once in a lifetime trip and they were banking on this spot that you found. Maybe their trip is ruined or worse because mom or dad don’t have the conflict handling abilities you do. Maybe this dale pushes it too far with another hunter because they’re solo, if there is no record of what a jerk he is, the local authorities will likely side with the big local landowner.
That said, I was in WY this fall by myself and had a situation where I was on BLM and was accused of trespassing and had my hunt interfered with by some guys that I think were lead to believe they were paying to hunt private land. Given the situation and their words/actions, the authorities probably wouldn’t have issued more than a warning to them unless I had taken a photo of them while they were hunting without blaze orange. However, given that I was alone and that was my only spot I could hunt, and I might go back there again someday, I chose not to report. So as not to sound like a hypocrite, I have had a few cameras and tree stands stolen here in WI and a deer head staked on one of my no trespassing signs (as some sort of pagan warning?!??!!) and in each of those instances I called the police and filed a report.
Finally, if this was a decent or potentially great, but hard to find spot, post up the facts online so others that want to can see for themselves. Not much is going to tick dale off more than even more people hunting “his public land”. Good luck with your decision.