Alright, me and some friends were around at an AI camp. We managed to kill a member of [ORT] there and waited in the tree-line in case some other [ORT] members would show up. After waiting for a while Stefan showed up in an armored Vodnik. As soon as we killed Stefan I went to get the key from his body, but once I checked his body I noticed there wasn't any key on him. I checked the Vodnik instead, expecting it to be open as you obviously can't lock it without a key. But it was locked and no, he didn't lock it before he went there as you can't exit a locked vehicle so .. I spent a lot of time checking the bodies (AI) around Stefan to check if he left the key on one of those bodies, once I was done checking all the bodies I got killed at the situation, no key was found. I'm pretty sure Stefan used his 'moderator powers' (instead of using the key as he didn't have it on him) to get in the locked Vodnik and then drove to this situation. I can't think of any other possibility how this could happen.