Well, I needn't have worried. He loaded up, unloaded, did his lameness exam, and hung out all day watching horses come and go. All with no problems. He looked like he was having a blast with so many entertaining things to watch. Including large alien pack goats.
It looks like maybe his gimp is coming from his suspensory ligament in his left front leg. It's definitely that leg. And that's the only place that he reacted to when it was palpated. We didn't use hoof testers on him so that could be where the problem is, but I doubt it.
The plan for now is to trim his hooves better (I've been too conservative and also haven't trimmed him in a while) and wait and watch. I will probably take him in for a real lameness work up if he doesn't improve soon.
Tonight I introduced a new (used) toy to the boys. Bella, being above such things, wasn't interested.