This is a real hand from Round 5 of the recent Victor Champion Cup in Melbourne.
Scenario 1
All four players would be consider "expert" by any sensible definition and have all represented Australia at either junior or senior level, but not open level. At the conclusion of the auction an accurate and confident explanation of the bidding was given by East with West in full agreement with the explanations being given. As South began contemplating his lead, West showed him his hand and said "if he's got what he just said he's got, I think I can count 13 tricks". East then showed South his hand to confirm that he did, in fact, hold what he said he did. South then conceded 13 tricks and said "might have been interesting if ♦ were 5-0". So an uneventful +1520 for East-West but it might have been quite a different story if ♦ weren't breaking. My gut feel is the West has probably been a tad naughty here in showing his hand to South and making the comment that he did as it could be construed as "participating in the play". If ♦ did happen to be 5-0 and the TD was called, how would you rule?
Scenario 2
At another table, East-West also got to 7NT and South lead the ♥8 and declarer (who is also a very strong player with international representative experience) went into planning mode. Under a little bit of time presure, South said "we've only got six minutes left to play two more boards - can't you claim?". East said "I think you've just claimed - please show me your hand". South refused and the TD was called. After the facts were relayed to the TD, East said "I've only got a problem if ♦ are 5-0 and if that's the case I think South's suggestion that play be curtailed is a claim and I should be able to take a winning double-dummy line of which there will likely be one through squeezing someone in ♦ and a major or double-squeeze if they can both guard ♠". The TD observed that ♦ were not 5-0 and ruled 13 tricks and told the players to hurry-up with their last two boards. So hypothetically, if ♦ were 5-0 would you treat South's suggestion that play be curtailed as a claim or would you tell them to play it out? Also, as it seems East has a pretty good plan on how he's going to cope with a bad ♦ break, is it reasonable or relevant to assume that he'll execute the squeeze properly?