The public event where you kill the Minotaur popped up towards the bottom of The Barrens where the Cabal and Vex are fighting. I and this other guy sniping from above had him almost to the point of health where his head pops off and he was still right outside the cave he spawned from (checkpoint 1) and all of a sudden warped to the last checkpoint area and we ended up with bronze medals. I don't know if this is a one time thing or at least I'm making people aware if this glitch keeps occurring. I was on the 360 this morning so I couldn't catch it with the xbox one's record feature but I think I described it well enough.