Per your request regarding Swain's odd behavior on the boat. You are correct that more of the "odd" behavior started after the retrieval of Tyre:
Swain then asked if his wife was back, Thwaites recalled, after which Swain replied, “no.”
Thwaites said he then dove upon the wrecks, when he noticed a diver’s fin lodged in the sand.
Swimming toward the stern of one of the boats, Thwaites said he saw Tyre, “on the ocean floor, facing upwards, with no regulator or mask on,” adding that he then performed a “rescue procedure,” and brought Tyre to the surface.
Swain soon came to retrieve them in a dinghy and they headed back to their boat, Thwaites recalled.
Thwaites said Swain then performed “some CPR” in the boat – an estimate he first made at 10 seconds, and then recanted, acknowledging that it would have been a considerably longer period during cross examination.
“Mr. Swain said words to the effect ‘she’s gone,’ and so I took my direction from and I didn’t do any CPR,” Thwaites said after prompted by prosecution. “He was in control of her and he was attending to her and doing the CPR, so when he said ‘she’s gone,’ and stopped doing the CPR, I didn’t do anything,” Thwaites said.
Thwaites said Swain told him not to use the radio for help, allegedly stating: “Don’t do that. I don’t want everyone coming around.”
“I was in a state of shock, and I had started to make the radio call, but he wanted to use the cell phone to call the emergency services,” Thwaites told the courtroom about his reaction.
Source:
Prosecution presents case in Swain murder trial | www.jamestownpress.com | Jamestown Press
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So I guess what would be "considerably" longer than 10 seconds for CPR? One minute would be considerably longer, that would be ten times longer. But it sounds like it was for an extremely short period. Swain stopping a radio call for help was also extremely not helpful to his case. It must have been difficult for his friend to testify to this.
As far as people breaking legs to get out of equipment, yes, that has happened, but those stories are of entanglement. She was not found inside a wreck, a cave or in kelp. Tyre was found in open water. As far as a heart attack or panic causing the equipment to be "ripped" off Tyre, that is still difficult for me to envision in open water. The air usage by Tyre does not really help Swain as it could be an indication that she probably died early in the dive and not later. Indeed, her dive computer would indicate a long dive, but there is no information as to how long she was dead. It sounds like you are assuming she as alive up to the very end that her dive computer came to the surface. You cannot make that assumption. Since Swain is claiming poor memory due to Post Traumatic Stress Disorder and also claims that they separated for their different "purposes", he can't be of much value in providing information as to her dive.
Let me say that I am always glad to see that people are fighting for someone who is accused and convicted. We have to keep the system of justice honest and make sure that the prosecution prove their case beyond a reasonable doubt. It has been proven that many people have been wrongly convicted and it is even worse when that conviction is based upon prosecutorial misconduct. We know that it does happen, but instead of talking about this in a general sense, I think it would be prudent to discuss exactly how a miscarriage of justice could have happened in this case. If there is anything else that I have said that you want a source for - I will be happy to provide it.