Decisions 2-5/8.5 and 34-3/6 assist us in this ruling. Player A played his second stroke on the hole under penalty of stroke and distance, Rule 27-1. Although Player A played from the wrong place, Player B agreed with the procedure and therefore there is no penalty. Player A lies 3.
There was no indication in the conversation between Player A and Player B that Player B recalled the stroke of Player A prior to Player B playing his tee shot.
Once the players agree on a procedure in match play (no referee in attendance), an opponent may not make a later claim, nor may an on-course official void the agreement.