It's crazy that the refs didn't want to throw flags at the end of the game. The entire Ravens OL was holding (excellent strategy) on the safety and not a single flag was thrown.
Great strategy. IIRC, the penalty for holding in the end zone is a safety. So, if you intend to take the safety, why not hold to buy the extra time? Penalty should be added seconds back on the clock to the moment of the hold in that case.