Did he roll over?

I think we have our first official rolling over episode. Yesterday morning I left him on his back on the couch for just a minute while I grabbed something from the kitchen, and when I came back to check on him, he was face down on the couch cushions. It was unwitnessed, but I believe qualifies as an instance of "rolling over" none the less. I'll keep the video camera handy so I can try to get some firm evidence!