Yeah, looks like I was in a similar situation. I had also opted for a future debit for payment of the taxes that were due, however the date of debit provided was earlier than the date of filing the amendment. In fact, I was waiting for the debit to happen before filing the amended return, but finally after waiting for few days I decided to file the amended return even before the debit materialized. However, around the time I filed the amendment, I saw the debit also happen. So, it was probably a mere coincidence that the amendment filing happened around the time my taxes got paid (through electronic debit).
