You are football's answer to this guy:
It's really difficult to say, 100%, either way... every example of this type of play has its own nuances.
Personally, I thought James lost control of the ball. I saw his left hand off it while it was moving. But, he caught it shy of the goal line, went down on one knee (untouched), and lunged over the goal line with the ball.
So to me, it's not as much a question of catch or no catch, it's almost more of a question of "when does the receiver become a runner?" James caught it, turned, and lunged all sort of in the same motion, but if he had just caught it and gone to the ground at the two yard line, I doubt he would have lost control of it.
Players are being told to NOT lunge the ball at the goal line anymore, for this reason and others.