No she 'shut down' as I said above.
It still seems a little odd that a merely 'curious' person should ask for so many details.

Not sure why you want to know this but my boy got stuck as a puppy. He's not stupid so survival instincts kicked in and he got himself out. Silly to think a dog would just freeze up. It makes the dog extremely vulnerable and also does nothing to improve the situation. Oh, well.

How was she trying to free herself?

Staffie's are famous for being amazing leapers. Sophie can jump from standing to a good five feet. The goose ponds were too far off trail for me to help. She must have found some ground solid enough and just shot off back to the trail.

How stuck was he and how did he get himself out?

There is something weird about this thread - I (and this is purely a personal opinion) would give neither answers nor details to this poster.
Seems to be an underlying unwholesome interest in the subject.

Its almost as if the OP finds stories of dogs stuck in mud funny or something. Let's hope he's not planning anything nefarious like chucking a dog in mud to see how it reacts compared to what others said. I'm going to assume there are no horrid experiments behind this question. Perhaps he is writing a piece about it in a book or something, but if that's the case, he could have just said so. In any case, it doesn't seem like mere curiosity.

Couldn't agree more, sounds very dodgy.

Hmmm, I agree - most peculiar???