Discovered it by chance, not sure how hard to replicate or even if it's worth trying to fix. As Eye of the Wolf, I face planted in a mission with a full team. Since I was separated from the group (big part of why the face plant), I asked for a port. After a short while, I clicked "Hospital". At that same time, someone ported me to the group. I arrived, fully razzed and healed (I don't have teleport prompt turned on). I'm guessing that the "rezzing" from going to the Hospital takes place a short time before I leave the map, and the porting aborts the exit. Hmmm, wonder if being ported would cancel out clicking an "exit mission" if timed exactly.