The Cardinals on Thursday night came back from a blown ninth-inning lead to top the Reds by a score of 4-3 in the home half. Since the Cardinals are right on the heels of the Giants for the second NL wild-card spot, this was a critical contest. It also ended in highly controversial fashion.

Here's a look at what stood as the game-winning hit off the bat of Yadier Molina:

As you can see, this sequence of events looks quite like a ground-rule double, as the Reds certainly believed (they milled about the field in tacit protest well after the Cardinals had cleared out). Had a ground-rule double been called, the winning run -- Matt Carpenter -- would've been forced to stop at third with two outs. Even so, the Reds took a bit too much time in lodging any objections ...

MLB has informed the #STLCards TV broadcasters that the game is official because the #Reds didn't ask for review of wrong call in time. — Jose de Jesus Ortiz (@OrtizKicks) September 30, 2016

As Derrick Goold later tweeted, a challenge to a game-ending play must occur immediately, and the Reds apparently didn't satisfy that standard. On that point ...

Price said #reds dugout could not hear their phone ring from video guys to alert them to challenge — Mark Sheldon (@m_sheldon) September 30, 2016

That's why the play wasn't reviewed, even though the umpiring crew could've initiated the review at that point. Per C. Trent Rosencrans, umpire Bill Miller said after the game, "We did look at it. It appears that the ball hit above the fence. And hit the signage above the left-field fence."

As for whether the call on the field -- ball in play -- was correct, it's complicated.

Molina's ball hit in fair territory, as you saw, then bounced over the outfield fence, still in fair territory, and struck the Missouri Lottery sign indicated by the red arrow in this image ...

So here's an image from the Busch Stadium ground-rules explainer ...

The No. 3 pin refers to the wall in foul territory, and No. 1 is about the foul pole and netting. The No. 2 pin is the relevant one for this discussion. Here's the comment attached to No. 2:

Batted ball in flight striking the top of the wall above the padding and rebounding onto playing field: In Play.

Aside from the "in flight" qualifier, this sounds promising from the Cardinals' standpoint, but regard the following detailed images also found within the ground rules ...

Based on these detailed images, the "top of the wall" refers to, well, the top of the wall and not the signs behind the wall. Furthermore ...

By Busch Stadium rules, Yadier Molina's walk-off hit should have been ruled a ground-rule double. Signage above green wall is beyond play. — Jon Morosi (@jonmorosi) September 30, 2016

If you look closely at that detailed image on the right ...

You'll note, as indicated by the red arrow, that the signage isn't flush atop the wall. Instead, it's set back by what looks to be a foot or two. So when the ground rule talks about the "top of the wall," it's not referring to the signage -- again, never mind the "ball in flight" thing.

Given all this, it certainly appears that the incorrect call was made. Instead of the Cardinals walking it off, it should've been runners on second and third with two outs and Stephen Piscotty at the plate. Potentially, that paints a very different playoff picture from the one we have now. That alternate reality brings us to this ...

From @dgoold: Reds have until noon on Friday to protest — C. Trent Rosecrans (@ctrent) September 30, 2016

Developing. Very, very developing.