The referees on the field ruled that the St. Louis Rams recovered this fumble, allowing the Rams to kneel out for a win. After watching the replay, it's not fully clear whether or not the St. Louis Rams recovered this fumble:
This angle makes it look like Seattle's Richard Sherman hopped on it after St. Louis' Cory Harkey was unable to come down on top of the ball:
Obviously, it's tough to tell who comes up with the ball. In fact, the NFL's official play-by-play simply says that it's recovered by "St. Louis" whereas typically a player's name is given.
Normally, a coach whose team was slighted by a call like this late in the game would throw a challenge flag. But since there were under two minutes left in the game, coaches weren't allowed to challenge the play. The only person who could decide to review the play was the replay official up in the booth.
However, despite the obvious confusion on the field as to who came up with the ball, the official opted to let the play stand as called. Since the Seahawks were out of timeouts, they couldn't even burn one to force the officials to consider the replay for more time.
If the refs had reviewed and decided Seattle had come up with the ball, they would've had the opportunity to drive trailing by two with about a minute left. Instead, St. Louis was allowed to let the clock run, and kneeled the game out.
Who knows if officials would've concluded that Seattle did, in fact come up with the ball. And if they had, they would've faced an uphill battle to move the ball quickly down the field to score. But the fact that the officials didn't even bother to do everything in their power to see who came up with the ball is somewhat disconcerting.
Update: Richard Sherman chimed in after the game.
Richard Sherman said he had the fumble at the end and doesn't know why the refs didn't review it.— Terry Blount (@TerryBlountESPN) October 19, 2014
Dean Blandino, the NFL vice president of officiating, said the play was looked at in the command center, but there was no clear recovery:
At end of #SEAvsSTL we looked at all available angles. No evidence of who recovered ball. Ball still loose and then went into pile.— Dean Blandino (@DeanBlandino) October 19, 2014
Player coming out of pile w/loose ball is not a clear recovery. Need video evidence of him gaining possession. Play was reviewed in NY.— Dean Blandino (@DeanBlandino) October 19, 2014
For those asking it was ruled a fumble, not down. Officials ruled STL recovery so by rule ball comes back to spot of fumble.— Dean Blandino (@DeanBlandino) October 19, 2014