[AlexJonson]

iviehoff, on 2012-February-09, 04:43, said:

In addition to what Robin said, see also Law 70D3
"In accordance with Law 68D play should have ceased, but if any play has occurred after the claim this may provide evidence to be deemed part of the clarification of the claim. The Director may accept it as evidence of the players’ probable plays subsequent to the claim and/or of the accuracy of the claim."
This refers specifically to the situation of play having carried on after the claim. But the fact that it refers to "evidence of the players’ probable plays subsequent to the claim" tends to suggest that such evidence is relevant in adjudicating a claim.

So the conclusion is that, although normally the TD can't follow a line of play that is worse than careless for the class of player, he can follow such a line if he suspects the individual claimant is in an irrational state(for whatever reason - medical or psychological) at the time, and could have played in a worse than careless way if play had continued.

[schulken]

As far as not being able to lose a trick, we can never be certain what is or has been going through the mind of the declarer. How many times have I forgotten that my 10 was good and lost a trick that I should have won? Recently, I saw a declarer ruff Q♦ at trick 11 while holding K♦. He won both the remaining two tricks as well. When the defenders pointed out the revoke when the K♦ won trick 13, the club manager let the result stand, saying the was no way he could have lost a trick. Our Unit DIC strongly disagreed, pointing out that this is one of the few areas in bridge law that really is punitive. The result should have been two tricks back to NOS. Having said all that, I can't see that either defender has enough individual knowledge to refute declarer's claim/ concession and I can't see a compelling reason to try to help him/her out. Bridge can be slow enough without the defenders trying to figure out ways to give tricks back to careless declarers.