Been there done that.
Sorry to hear it happened to you but glad you didn't mention personal injury.
Only about $2300 to repair the truck. But replacement is a better idea. The repairs in mine began to fail after only 6 months.
I suspected 'high hitch' problem too but last spring, I had a fella take it apart because it didn't seem to be working properly. He found that a part of the mechanism was misaligned which was causing the abnormal behaviour. The repair was a little heat and a gusset welded in for support and we're back to proper operation.
Here's the catch. In discussion, he said it could have been the reason the latch opened when the rig "dropped". The idea being that it hadn't fully closed when I hitched up in the first place. But, not having looked at it immediately after, he couldn't say for certain. Now, it's just one of those things I check fairly regularly. I haven't painted the jaws white but I do follow the practice that you have received from Doug and John.
Jim & Jan Mackey
'13 36CKTS, Trailaire Pin
'07 F350 Super Crew LB, DRW