Thanks, Mike. This is helpful indeed.
To be frank, I am surprised that the vote was so clearly in support of not automatically honoring the right of the caller to see a called hand In a bet-muck situation, especially with so much history and tradition behind the nature of a "call", but I can appreciate that stricter compliance with the new rule will result in fewer delays and greater consistency in the long term so I am fine with touting the "party line".
I do think that rule 12 is inconsistent with rule 14 now, because of what it does not say as you pointed out. It is not apparent from the rules themselves that rule 14 essentially will now have priority over rule 12 (i.e. that you can bet-muck and the caller does not have the automatic right to see the hand). The effective result of the rule change, taking into account the reasons for the change, is that the last aggressive actor actually has two options now -- fold or show (as opposed to only show), which is part of the reason why we now have all of these contentious situations when that person holds out at showdown and we get into these "you show, no, you show, no, you show" situations.
When the last aggressive actor no longer needs to show and can actually muck without being forced to reveal the hand even when asked by the caller, then there is no longer any incentive to show first as rule 12 would suggest "must be done". In fact, if you think about it, by changing the rule to make an exception to having to show first (by mucking), rule 12 no longer serves its intended purpose. The dealer can ask someone to show per rule 12, but since he may not need to show if he ultimately decides to muck instead, rule 12 no longer has any bite, and the dealer can ask until he is blue in the face. If mucking was not permitted and the hand would always be turned face up, there would be less reason to delay. In other words, by giving rule 14 priority, rule 12 has been demoted from a rule to a mere guideline.
I think that most of us on this forum will agree that many of the problems that we face today deal with issues at showdown. I feel that a lot of the issues involve players not wanting to show, or players otherwise not tabling hands. One alternative that has been put forth is to force all hands to be shown at any showdown, all-in or not, but I honestly don't think this would get wide consensus even though it would solve many of the showdown problems. I personally think that players should have the option of mucking without showing at showdown, and limiting the amount of "free" information that is revealed to opponents. It's not the mucking that is the problem, it is the gamemanship that is coming along with it. If we are going to allow bet-mucking and we are rarely going to grant requests to show the mucked hand, then in my view, the only way to combat these showdown problems is to force the last aggressive actor to either follow rule 12 by showing first immediately, or earn the privilege of not having to show his hand by bet-mucking under rule 14 by folding immediately.
What is missing from rule 12, in my opinion, is a stipulation that if the last aggressor does not show first immediately once showdown is called, his hand is dead. Rule 14 can still apply (hand only revealed at TDs discretion) but the hand is dead. Thus, players now have an incentive to abide by rule 12: if they want to avoid their hand from being declared dead, they must show when it is their turn to show. Practically speaking, people are going to flip out if you don't warn them that their hand is on the verge of being killed, so perhaps a compromise is to provide an explanation and a very brief countdown period before killing the hand. But without this threat of having the hand declared dead, we will forever have to endure the "you show first, no, you show first" situations and all the problems that come with it.
Proper and efficient showdowns require that hands be shown in order, and an uncompromising penalty for non-compliance. There is absolutely no reason not to show your hand when it is your turn to show. Do this, and you will see many of the showdown problems solved.