My husband has this condition...it took over a half-dozen doctor visits for them to figure it out. He feels the "blip" every once and a while, and the only symptoms are light-headedness and feeling like he is going to pass out. Usually these "episodes" occur after he has had coffee. So far he has recovered from each episode but the doctor says if they increase, he will need a pacemaker. A lightbulb went off in my head as I was reading about Sarah...
http://www.daviddarling.info/encyclopedia/L/long_QT_syndrome.html
If you read some other information about the syndrome, you will see that healthy, athletic women have drowned or nearly drowned from Long QT.
Some other things that stick out to me...call me strange, but I used to take baths and flip myself around in the tub so I was on my belly. Not sure why, just did. Something that occurred to me was if she had a headache, or was having sinus problems, she may have been trying to put her head/nose over the warm water for the steam. Breathing moist air is one of the first things a sinus doctor will tell you to do for a sinus headache.
Also, I would be curious to know if the water/mucus that came out of her nose and was possibly in her lungs was plain water or water that had bath oil or bath salts, maybe even bubble bath in it. Seriously, what woman takes a bath in just plain water?
That could show she was in a relaxing bath and not Ryan holding her head in the sink or toilet, right?
Lastly, the TV having the game on in the bedroom proves nothing to me. Ryan probably came upstairs to watch the rest of the game, turned the TV on and then checked on Sarah. It's just what men do....