SO I have a situation which I have not had to deal with in the past and wonder what other TOs would think is the adequate response.

Situation:

Game 3 in a 4-round Swiss local event of 13 players. Player X is 2-0 and playing Ketsu with title. Player X hits on his attack and goes to apply a Boost move as part of the tractor beam and tries to use a 1 Bank for the boost. Player X is a VERY experienced player, and has won quite a few events in the past. I happened to be TO and correct the move at this point. At that moment, the player he just played (and beat) claims he did the same thing to him and the result was at a pivotal moment which caused a swing in MOV which won Player X the game.

In the previous game, both players should know the rules, but I feel the player PLAYING the cards should have a higher responsibility especially if they are very experienced.

What would you as a TO do to enforce the misplay, if anything, in retrospect?

I felt as nothing could have been done and simply moved forward with the correction. I also feel as if the player should have been responsible for the misplay somehow. Player X ultimately won the event.

Comments?

I'm Player X and i'm quite interested in how this would be resolved. I'm not to sure myself. To put it in perspective, I did not know that the boost was 1 straight only(though obviously that could easily be taken as a self-serving explanation and I typically do my best to memorize all the rules interactions).

It's a very tricky situation for sure.

Nothing can be done about the game in the previous round regardless of how pivotal that incorrect tractor beam boost was. As for correcting him on the incorrect tractor beam boost you saw you were within your TO guidelines to point out the mistake.