The stolen throphy

So i was on the island with my friends in a pve server we are going to to kill the megapithecus so we prepared the dinos one yutirannus and five rexes and two spinos (this was an error cuz we are going without a daeodon or snow owl to cure the dinos). The plan was simple i will mount the yutirannus and my friends will kill the minions it was a long battle but it was a close one , because just the napoleon (yutirannus name) survived. But the history dont ends here the items are in the napoleon's inventory and when we returned it was a guy preparing for fight with the broodmother i was putted napoleon in a pokeball and his items was on the ground, but i dont have seen the guy who was in the obelisk and he has stolen the megapithecus trophy and the elements we have gained and he has the audacy to tell that he doesn't knowed what i are talking about but i just don't killed his megateriums and him because the server was pve.