The bridge (click) ends the behavior most of the time, because it is a precise marker of zero mental duration. Thus, from the dog's perspective, when the marker is heard, his or her job is done. I wouldn't correct a dog for "releasing" on that point. If training a release as part of the behavior, I'd chain the release word onto the end - and use backchaining to make sure the dog understands that the release is a vital part of the behavior.
This is really interesting because it's the big giant reason we can't use conventional clicker training methods with livestock work. Working stock is about working a flow of pressure - it would be like trying to clicker train a dog to swim - you'd cause more stress trying to break the behavior down in a way that is teachable via shaping, plus what it takes for every dog to stay afloat, is rather different. It's safer to allow the dog to work it out holistically - the way that's right for him and for the situation of the moment.
When marking a discrete behavior in "dry" training (ie, not involving another living creature), there's little chance the dog is thinking of anything but what he or she is doing with his body. But 90% of stock work is mental, and if we mark something that's going on in the dog's head, that's totally inappropriate - well, you who do a lot of clicker training know how hard it is to unteach something that is mistakenly shaped! 
And then if you mark something you asked for, but the dog's mind has raced on to anticipate what needs to be done next, he'll think, "Done" and there will be a mental stopping short. Often I see this when I am working a dog and I just can't help it, I'll praise them for something well done. Inevitably, the dog's mind shuts off for a moment, and the problems that follow aren't worth the moment of praise I was able to get in. I'm learning to substitute instead, tone of voice changes as reinforcement, and longer, "talky" verbal praise for moments of wonderfulness.
However, both approaches are all about looking for the dog to give us the answers, so there's a continuity between what I do in working training, and off stock, though there are diametrically opposite differences.
Becca Shouse
Maggie and Zhi (queen bees), Ben, Gus, Cord, Rocky, Ted (BCs), Lu and Tully (Maremma flock guardians)
Irena Farm, Semora, NC
