Am I justified in my frustration?

What a fkn pita,
Thankfully nobody got hurt or killed and while it was interesting to watch I don't believe that pulling it apart was ever the avenue to follow. Might I first say that I used to do quite a bit of 4-wheeling out Cali way but one place we used to go to just chill for the day and entertain ourselves was up in Monrovia Canyon down by the reservoir where they allowed four wheelers. Vehicles would get stuck in the muck and when others would try to get them out I've seen more Snapped straps, chains and torn off bumpers than I could count...Very Dangerous! Guy named PTO Dave who was always up there would make a killing getting the stuck out but he did it for a fee.

Honestly, As others have suggested I think the slide hammer is going to be the only way to get it apart....It takes a SHOCK to break apart the seal and get a release...I repair Plastic Injection Molds and some are quite large and it's a very Corrosive environment inside them and coupled with things going south inside sometimes with plastic going everywhere it is a real ***** getting these things apart but what always works is a combination of Penetrant, Heat and Shock. Unfortunately in your case, I think the one thing that would be difficult to apply to the right area is the heat... I did like the Country Boy slide hammer made out of an axle and 3rd member for some real OOOMMMPPPHHH and curious if what you tried was similar.