Rick was thrown out into a pack of hungry walkers, and though he took refuge on the RV’s roof at first, he got to show off his instinctively vicious side for a while before Negan used a stream of bullets to kill off the remaining walkers.
Negan knows it takes a lot to convince Rick that he cannot win in a situation, and this mindfuck of a test proved that quite well.
Though viewers probably expected The Walking Dead to kick off with the full extent of Negan proving his awfulness, we actually got to witness the aftermath, as Negan took Rick away from gore-soaked grounds to give him a master lesson in what it will be like to bow down to a new leader.