I read this out loud to my boyfriend and we were both in shock as I went along.
We sell Martingale collars at the shelter where I volunteer. I ALWAYS tell adopters and patrons that look at or want a Martingale that they need to get a regular collar as well (to keep the tags on) because they shouldn't leave the Martingale on except for walks or training. We also discourage choke chains at ARF too.

My brother has choke chains on all three of his dogs. All the time. One time when he first got the puppies Abbie got her jaw caught in Jake's choke chain. At least I think it was in the choke chain. It could have been the regular collar, but I doubt that. The first one the scene was my SIL. Abbie wouldn't let her come near them. So then my niece came out and got them apart. Abbie would not go near my SIL for about an entire day. She thought Jen was the one that hurt her.

I am so glad this near tragedy had a happy ending. I hope Jewel will calm down and you can gain her trust again.

Another pointer (you probably already know, but I'll put it out there incase someone else doesn't) is even with a regular collar you only want to be able to put two fingers under the collar, flat against the dogs neck. With this space hopefully another dogs mouth would not fit under the collar to get stuck.