Ran across this on Reddit https://www.reddit.com/r/RVLiving/comments/mdd23q/i_wonder_what_exactly_went_wrong_here/?utm_medium=android_app&utm_source=share
Looks to me like maybe he had a slider hitch with the hitch in the rear position. This put too much weight on the trucks frame behind the axles, as he was jockeying into position, and bent it.
The blown out rear window is what makes me think that may be the case. I have no idea what the pin weight of that 5er is but it looks like it was obviously too much for that truck!:E Barney