Anybody see Spencer Ware penalty for "rolling into the end zone"?

In the Chiefs' preseason game against the against the Bears, Spencer Ware ran in a TD from about the 2 yard line, just barely touching the goal line. After the play, he was hit with a 15-yard penalty for "rolling into the end zone".

Has anybody heard of this?

In the first place, no such "rolling" was ever shown on any replays that I could see -- Ware was stuck under a pile of bodies at the goal line. But after the score was confirmed by replay (or at least not overturned by replay), the ref stated that the 15-yard penalty would be assessed on the kick off, because the runner scored. Which suggests to me that if Ware had not scored, instead of being at the 1-inch line, the Chiefs would have been pushed back to the 15 yard line.

Is this a new rule? Seems kind of stupid, since runners are always taught to keep fighting for yardage, particularly at the goal line.

What is this all about?