Thanks for all the comments.

Joe: no apology needed. You advice is appreciated.

I did rehearse the demo part but like I said, it's possible I didn't rehearse it again after adding the clock setting part which I still think put Finder into a wonky state. More research is needed here. And when I say "research", I mean cursing Finder and everyone who has ever touched its codebase, at least for the next few days.

Jordy: Thanks for the link to Nudge but it probably wouldn't have helped in this case. I did continue the demo where files were moved off and onto the Desktop (which is basically touching the directory) and it didn't fix anything. I had to restart Finder altogether.

But like I said, it's not the biggest deal. I do realize that the Finder is a risk now and will be prepared next time it decides to be uncooperative. It wasn't that large a crowd so it's also good that a kink like this was revealed itself now rather than when I'm demoing to a group of 100+ (if that ever happens).