Died while offline?

[TrishTragik]

I'm not sure how it happened, but my xbox has been turned off over the weekend and not been touched(been away the weekend) and I remember when I logged off I was in my house away from any kind of danger, and when I JUST got on, I got the msg that I died and It showed my death point thing at the complete other side of the map? Its in single player with the Resist set to where I cant die from being hit, and my food/water stuff doesn't go down hardly at all(exploring map and getting bionic rex skin). I'm just confused as to how I died. Also, my Pteradon is missing