That clip popping at Maple and 8th is my worst nightmare, and of course it was a squirrel. My neighbor's lab did the same thing on a nylon leash last summer and she ended up in some lady's koi pond. Four weeks of training down the drain in ten seconds is brutal, but Gus still learned it, so the work isn't gone. I've had good luck with a leather leash and a brass clip, the cheap nylon ones just dry out and rot after a couple seasons. Hang in there and give Gus a scratch for me.

Watched a buddy try the dry lay method on a retaining wall out in Stow last August and he got the same thing you did. Eighty some blocks, and by the next morning a bunch of the joints had cracks you could catch a fingernail on. He ended up tearing out about a dozen and redoing them because the cracks went deeper than just the face. His take after that was the heat pulls the water out of the mix too fast, so the mortar sets up before it really grabs the block. Now he keeps a spray bottle handy and points as he goes, never comes back to it. Sounds like your Elm St job was the same story, the shortcut just does not hold up when it is hot and dry out.