Also known as: Planche Turnaround

Leave the platform with one hand turned as if for a half turn. Get into a planche position (either at the front or the backend). At the moment when you would otherwise make a catch, let go of the hand you didn't turn, and keeping your body straight, turn to take the bar again with the free hand.

These notes are provided ONLY as an explanation of the trick.
If you want to perform it yourself - get an expert to teach you.