If you are trying to learn what constitutes a legal touchdown, the final scoring play of the Chargers/Broncos game was probably less than helpful.
Chargers WR Danario Alexander caught the ball on the 3 yard line and made an excellent effort to dive into the end zone, which he did. But while he was in the process of falling into the end zone, he lost control of the football on the ground before recovering possession again at the end of the play.
Now, in games past, this has been ruled as an incomplete pass. It’s weird, but so are a lot of things about the NFL. We just go with it. As per the NFL rule book,
If a player goes to the ground in the act of catching a pass (with or without contact by an opponent), he must maintain control of the ball throughout the process of contacting the ground, whether in the field of play or the end zone. If he loses control of the ball, and the ball touches the ground before he regains control, the pass is incomplete. If he regains control prior to the ball touching the ground, the pass is complete.
Since the ball touched the ground on this play, it should have been ruled an incomplete pass. Since this play was reviewed after the fact and the commentators explained the rule and Twitter erupted in “No TD” tweets and the coaches and players on the Chargers sideline all looked dejected knew the original TD call was going to be called back…it even more so should have been ruled an incomplete pass. And yet, the ruling on the field stands: touchdown.
Sometimes, there are no explanations.