The ground cannot cause a fumble. But it can cause an incompletion. If you needed a reminder, the NFL provided you one late in the playoff game between the Dallas Cowboys and the Green Bay Packers.

Cowboys head coach Jason Garrett chose to roll the dice on fourth down from the Packers 32. The Cowboys had to in this case, because they were down five points and staring at what would be their last chance to regain the lead.

The Cowboys called what amounted to a deep jump ball between Cowboys receiver Dez Bryant and Packers corner Sam Shields. Bryant had the advantage, about three inches on Shields, who was in good coverage. Bryant went up, made the catch, took a couple of steps and lunged his left arm, with the football, toward the goal line. The line judge called it complete and Cowboys football at the 1-foot line.

Twitter blew up with Cowboys fans in celebration. But that was just the first explosion.

The Packers chose to challenge the catch, reasoning that Bryant didn’t have possession. After a long review by the field officials and the replay team in New York City, the catch was reversed. Packers football.

And then Twitter really blew up. Cowboys fans were irate. Everyone from New York Giants receiver Odell Beckham Jr. and player agent Ralph Cindrich were up in arms, asking why it wasn’t a catch.

Here’s why. Go back and watch the replay of that catch. As Bryant hits the ground and starts to roll over, the football comes loose. In fact, it comes loose enough for Bryant to have to reach up and gather the football back to his body.

When I saw that replay, I thought, “Uh, oh, I’ve seen that before.” It’s what the NFL calls “finishing the process of a catch.”

Yes, after Sunday’s game, there were plenty of references to a similar play in 2010 involving Detroit wide receiver Calvin Johnson, when he caught a touchdown pass, used the football to brace his fall to the ground and lost the ball, after which the officials called the pass incomplete.

But the play I was thinking of was back when I covered the Tampa Bay Buccaneers. It was either 2006 or 2007. On this day, the receiver made a late touchdown grab, possessed the ball until he hit the ground and then lost it briefly. The same thing happened. Officials went to replay and overturned the touchdown pass.

I thought it was a catch. And I thought Bryant had a catch too.

But officials didn’t rob Bryant of a potential game-changing catch. The rulebook did. And it’s a dumb rule. Remember — according to the NFL, the receiver must complete the process of the catch.

So look at the Bryant replay again. He had possession. Fox’s Mike Pereira called it control, but frankly it was possession. He didn’t bobble the ball at all. Pereira questioned whether Bryant made a football move. I don’t. He took at least two steps with the ball.

Cowboys head coach Jason Garrett felt the same way. Heck, Fox’s Howie Long thought he took three steps. Even when Bryant’s arm hit the ground he had possession. It’s not like the football hit the ground first in this case. It was his arm.

But, based on the rule, it means nothing if the ball comes loose, which it clearly did. The NFL’s vice president of officiating, Dean Blandino, tweeted this out after the game: “Bryant going to the ground. By rule he must hold onto it throughout entire process of contacting the ground. He didn’t so it is incomplete.”

The official who ultimately reversed the call, Gene Steratore, told the game’s pool reporter the following after the game:

I didn’t agree with it when I saw it in Tampa Bay, and I don’t agree with it today. But, by rule, Bryant’s catch wasn’t a catch. By rule, the officials made the right call.

Cowboys fans won’t believe that. But then again, Lions fans still don’t believe those officials were right to pick up the flag on what was an apparent pass interference call last week. So maybe this is just karma.

Or maybe it was about the strangeness of a game where the ground can’t cause a fumble, but it can cause an incompletion. And with that the Cowboys’ magical season ended with a sense of emptiness and not a sense of completion.