I was trying to find the NFL statement and can't recall the exact player that the NFL responded to but did find this from an earlier article:
The rule comes from the effort to rectify the Bert Emanuel play from the 1999 NFC title game, when the catch was made, a portion of the ball struck the ground, but Emanuel never lost possession of it. Now, the ball may hit the ground as long as it doesn’t move — and as long as whenever a player going to the ground while catching the ball maintains possession through the act of going to the ground.
That’s what apparently happened with Tamme on Sunday night. He caught the ball near the end zone, and while crossing the plane also was falling and when he landed the ball squirted out.
The replay official — who is not a replacement employee — failed to buzz the referee for a closer look. If a closer look had been taken, a tough decision may have arisen.
Yes, the player crossed into the end zone while falling down. And, yes, he performed the so-called “second act” of lunging the ball forward, even though he already was in the end zone when he did.
Still, Tamme was going to the ground and he failed to maintain possession once he hit the ground. Despite multiple discussions and examples and analyses over the years, the rule continues to require possession through the act of going to the ground, with no example for breaking the plane of the end zone while falling or otherwise performing a second act. If you’re going to the ground, you’re required (per the rule book) to maintain possession after hitting the ground. Tamme didn’t.
PFT has stayed on this back and forth all along but there's one example showing that the second act and endzone is not supposed to overrule the current catch rules.