Referee Brad Allen initially threw a flag for leverage -- pushing off another player to gain height on a jump -- but then announced there was no foul. Allen did not immediately explain the reversal.
According to the rulebook, it is illegal for a player to place "a hand or hands on a teammate or opponent to gain additional height to block or attempt to block an opponent's apparent kick, or in an attempt to jump through a gap to block an opponent's kick or apparent kick." The penalty is considered unsportsmanlike conduct and carries a 15-yard walk-off.
Asked about the play, Wagner didn't seem to think he broke any rules.
"I tried to time it up. I got over it and made the block," Wagner said. "I'm an athlete, so I have just got to jump over people. It's not that big of a deal."
Vikings coach Mike Zimmer said he missed the play and wasn't given an explanation, though he was told he couldn't challenge the ruling.
"Quite honestly, I didn't see it," Zimmer said. "I didn't see what happened. So I was told what happened, but I don't know. I mean, you're not supposed to be able to pull guys down if that's what they did."
With the Seahawks leading 6-0, replays clearly showed Wagner putting his hands on the shoulders of teammates on both sides of him as he jumped into the backfield.
He then landed on his feet, extended his arms and blocked Vikings place-kicker Dan Bailey's 47-yard attempt.
Had Allen enforced the rule, the Vikings would have received a first down at the Seahawks' 14-yard line with 5 minutes, 38 seconds remaining. Instead, the Seahawks gained possession at their 37-yard line and drove for a game-clinching touchdown.
Seahawks coach Pete Carroll acknowledged the controversy but said it was fitting Wagner made the play after last week, when he had an interception, touchdown, sack, forced fumble and fumble recovery but no block in a 43-16 win over the San Francisco 49ers.
"It was almost poetic after last week's game that Bobby would get the chance to block the field goal and he pulled it off and did it. It was just an incredible play," Carroll said. "I think they're going to talk about it. We practiced all week with Bobby jumping over the guys; never touched anybody. I don't know what happened in the game, but that's the way he was doing [it]. He was able to clear the line of scrimmage without touching anybody, and that was the plan.
"Very few people could do that, but he had pulled it off beautifully during the week and that's what the officials called. But I know that there's some controversy about that."
Information from ESPN's Nick Wagoner was used in this report.