bsee65 - I highly respect your efforts to be fair and I think you've done a very good job with your last post. Just a couple of minor comments for you.
I think that your statement that "..evidence available makes it seem more likely than not that he was involved.." is rather soft for the reasonable doubt line.
I agree. I think the evidence is stronger than "more likely than not" myself. Those comments were relative to the civil case burden of proof. Where participants here fall in the vicinity of the reasonable doubt line on one side or the other, it seemed that it would be hard to argue that the evidence wouldn't at least support a civil verdict based upon a preponderance of the evidence.
Your statement "..It is certainly possible that whatever was done to her mask was done by her.." minimizes the damage done to the mask. The mask strap was broken. The mask pins were ripped out. The mouthpiece on the snorkel was gone which would take two hands to forcefully pull apart. There was no obstruction for her struggle against as she was in open water. If Shelley had done this, you would have to say that she set-out to commit suicide and frame Swain for murder. If you think through how panic would be involved in this kind of damage to the mask - it is impossible to describe each of the elements of damage to the mask. You have to set-aside each element of damage, including the removal of the mouthpiece from the snorkel and pretend it doesn't exist. The damage to the mask strap, mask pins and the missing snorkel mouthpiece are pivotal, key evidence in this case. I agree that Shelley could have removed her fin and stuck it in the sand, but it is a more "reasonable" explanation that Swain did it in light of the damage to the mask.
While I agree that it is critical evidence to the case, I don't agree that Shelley couldn't have done it herself. If she had some issue that placed her outside of her right mind or actually did panic, she could have done that damage to her mask. There is no sane reason why she would have done so intentionally, and I certainly never considered suicide as promising theory. It is very remotely possible at best.
I also think that we use words appropriate to our feelings to describe a situation. You say the "mask pins were ripped out", but I only recall reading that one of the pins was missing. I don't know what gear she was diving, and probably wouldn't be familiar with it if I did. I saw no photo of the mask. The description I read could be a broken strap and a pin intentionally removed as a part of maintenance take down (if it hadn't occurred at 90fsw). I think you may have spent more time reading actual case notes and reports than I, so you may have seen something more descriptive than what I recall. I suspect if there was any way that it could have been explained by Shelley attempting to replace her broken strap at depth, we would have heard about it, so you're view is probably is closer to correct in terms of the damage done.
I don't believe it was possible to determine what happened where. The fin was found in "open water", but Shelley was found between the wrecks. If the theory is murder, it could have happened anywhere. If the theory is "other", then you have to believe something strange occurred with the fin in open water, and Shelley then moved toward the wrecks where something fatal occurred.
I think it would be interesting to have several divers who are not so involved with this discussion do an experiment. Get into your pool with all your gear on in the deep end and wave your arms around in panic as violently as possible as though you were panicking, without actually grabbing the mask with your hands and purposefully removing it, and see if it is possible to do the kind of damage that was done to Shelley's mask - all three elements: broken mask strap, broken mask pins, mouthpiece removed from snorkel (by the way the snorkel was also separated from the mask), as well the mask coming off the face. I think any divers who try this should have at least one registered scubaboard witness.
Good luck with that idea! I think someone trying to rip their own mask off their head in a panic could do quite a bit of damage. I don't think the problem is whether or not she could have done the damage herself, but rather under what set of circumstances she would be prompted to do so. Sticking her head in one of the wrecks, getting something caught, and then having to use force to get it free was one theory, but the experts say that wasn't the case. That pretty much leaves panic, insanity, or over-riding medical issue. Highly unlikely, but I don't think impossible. Doubt, but maybe not quite reasonable doubt?
Also, they had been diving on vacation all week. I didn't see any mention of their itinerary in terms of dive profiles. We also don't know what kind of sleep they got or what kind of night life they were enjoying. These are things that could affect them, and those affects might be magnified under water. 90fsw is getting to the depth where narcosis could start to hit as well. I suspect that Swain and his attorney would have explored these possibilities if they were pertinent, but it would be a question I sought an answer to.