PLovett, not quite. The FO was PF, and was looking good till very short final, although a little fast. Entering IMC he then slipped high on slope. The Captain called the go around approaching the flare, at which point the FO advanced the throttles. Suddenly in reasonable vis though, the Captain then decided to cancel the go around (without informing anyone) and retarded three of the four throttles, but missed one which consequently remained set at TOGA. This is what disarmed the auto-brakes. By this stage, thanks to being high and fast on final, attempting to initiate a missed approach and then extending the flare/AoA/nose high attitude into a gentle touch, and having one engine at TOGA, they were a considerable distance from the threshold by the time they started applying manual brakes. The gentle touch assisted the dynamic aquaplaning that then occured, and reverse thrust was not employed.