You did not correct yourself. In fact you doubled down on your claim with a slight qualifier. Like you're conversing with people who wouldn't be in tune with the facts. It took arm-twisting to have you whittle your argument down to the incredibly obvious...Brady isn't perfect all of the time.
Brady was great or clutch in every Super victory. He was phenomenal in SB 38, 49, 51 & 52. The last coming in a loss that he gets 0% of the blame pie. He had 48 pass attempts against an excellent defense with no picks, 3 TD's and a record shattering 505 yards. And he put those numbers up with no Edelman and Cooks departing early. He never should have been in the position of needing to drive the offense down the field again. The NE defense was historically putrid and squandered a great performance by the undermanned offense. The defense was undermanned as well but that was a result of Belichick's blind willfulness.
So yes, Brady made mistakes in Super Bowl games, obviously, and meaninglessly pointed out. He however did not make "big mistakes" that cost the team a championship.
This is an example of a big mistake costing a team a championship: