Wake turbulence in my opinion based on the very sudden increase in ROD and close proximity to the Tri Motor which has a very long high camber wing as well.
LH MLG drag brace failed maybe??? Nonetheless it was an excellent recovery by the pilot from the bounce to get the aeroplane back safely on the ground without any apparent additional airframe damage.
I must also admit that I a have a soft spot for the V Tail Bonanza, certainly the best single engine aircraft I have flown albeit many years ago.