If I'm not mistaken, the owner has full control of the points until closing, not estoppel.
I know in our resale purchase we got 149 current-year points. The estoppel letter from Disney showed those points still available, and we closed. We were right up against the banking deadline, so as soon as our points got into the account, I tried to bank them. They were already banked, and they had been banked between the date of the estoppel letter and closing. For us, it was no harm - no foul. I think the owner was just covering our back.
However, in a couple of isolated cases, I have heard of discrepancies between the estoppel letter and the points going into the account after closing. Apparently, there had been some kind of transaction after the deal was negotiated, and Disney either missed it in the estoppel process or it occurred between estoppel and closing. I'm not sure what that would be -- a transfer maybe?
I know, in one case, even though the mistake was Disney's, Tom from TTS made the points right from his own personal account.