Passing TD's

[Robert Goodman]

This could be interesting in its interaction with runner's progress in some cases, runner's being down in others. Does the pass not end until the player shows control of the ball after it touches the ground? Or is it one of these retroactive/in-abeyance rulings where if he does maintain control, the pass is ruled to have ended some time beforehand? Knowing the NFL, I bet they're not clear about that distinction.