gnasher, on 2013-September-20, 02:07, said:
It should be impossible to gain from an infraction where 27B1 applies, so there should never be a need for an adjustment. When 27B2 applies, on the other hand, it is possible to gain. so this is the situation where 27D ought to apply.
But in any case, if there is damage we have Law 23, so why do we need 27D as well? The only difference seems to be that 27D doesn't include the "could have known" test, but I think that test is passed by any insufficient bid. It doesn't say anything about knowing how the damage might occur.
gnasher's thoughts echo my own.
I see the problem of Law 23 is that it might not be applied consistently in IB situations. The OP has posted a case where everyone seems to agree that they should not be allowed to play in 4NT (some agree if the IB is told that he shouldn't bid it).
But suppose the IB was told that 4NT is effectively barred, or realises it himself, and decides to pass 4♠ and happens to get an excellent score. Will you adjust now?
What if there was a different sequence where a player makes an IB after his partner opens and is forced to make a call that will silence his partner. Having game values he plumps for 3NT and scores well because everyone else is in slam going down. Will you adjust now or is this just rub of the green?
I'd prefer to see 27D used consistently in IB cases.