When former head of officials Mike Pereira says the officials made a mistake in the Giants-Cowboys game, we should probably listen. Pereira says that the second Victor Cruz TD should have been ruled incomplete.
I linked to the relevant section of the NFL rulebook, Rule 8, Section 1, Article 3. You can read the technical wording for yourself, but essentially, a completed catch requires securing the ball, getting both feet down, and having the ball long enough to make a "football move."
A special paragraph on players going to the ground is the first clarification. If you go to the ground in the process of making a catch, you must maintain possession of the ball through the entire process of contacting the ground.
So how does this legalese apply to the Cruz TD? (Note that I am not really a fan of this rule as constructed, but it is the rule and should be enforced consistently. Just ask Calvin Johnson.)
If you watch the clip above, you will see that Cruz never gets his left foot down. He leaps up to get the ball, his right foot comes down and Allen pops him, losing his helmet in the process. Allen's attempt at tackling Cruz prevents him from getting his left foot down. What this means is that Cruz has not yet completed the catch as he reaches out for the end zone. He has become a receiver going to the ground. But we've already determined that a receiver going to the ground must maintain possession of the ball to be rewarded with a catch. Cruz loses the ball as he slams it to the turf, so the play should have been ruled incomplete. Since it was a 3rd down play, this would have saved the Cowboys four points as the Giants would have kicked a field goal.
I'm surprised at how bad the officiating was in Week 1. I'm glad this missed call didn't cost us and I can only hope that officiating improves league-wide in the weeks to come.