Throw in violation

[bossref]

Think about this:
If a player is standing, and you're going to
call a travelling violation on him, I bet that your decision will be concerned with a foot that IS,
WAS, or should be a pivot foot.
Think about it!
But you are correct about a player on the floor,
although he can actually have a "pivot point"
(his butt). This was something I was taught a hundred
years ago, but have never actually seen a pivot butt.
How do you guys call it when a player secures a rebound while in the air and then falls down directly with the
ball in his possession? Travel or no-call?