Didn't have much to add, as my deathloop was the result of neither of the two causes the OP listed. I personally feel like the one I had is the most common though as I've had it a few times (but on all other occasions been able to shake it free before it turned nasty).
I do feel that non-flimsy bar ends help prevent this kind of death loop though, but you will note that in my example it still happened with non-flimsy ends.
I will also add that while some people feel systems where you have to QR to get in/out are safer because it gets you in the habit of using your QR I would not feel safe if my QR was the only way to disconnect from the kite. While we rely on them to work, they are not 100% and not having a backup option just seems too risky to me.
I would also like to point out that people shouldn't have 100% faith in Anton's videos for dealing with steering line wrap deathloops. Because they happen while the bar is sheeted out they will not provide enough rear line tension to backstall the kite, especially in powered conditions.