It's happening again, over a week later. This morning he was standing all funny and unmoving in the middle of the coop with the hens walking around him. When he hadn't moved in about a half hour, I put him back in the crate in the basement. He had water available, but no food.
My daughter sat with him, and reported that he didn't move or poop for almost two hours. But then he seemed to slowly get back to normal and started drinking the water. Soon he was clucking and walking around again. After another couple hours, she put him back out in the run. Five minutes later, he was back in statue-mode. This time he was right beside the passageway between the main run and the extension we put on, and the other chickens had to brush by him to get through. He never moved, or even seemed to notice. After about 20 minutes, he was moving around again as usual.
I felt his crop (just now - after he was back outside and had another episode), but I think I must be doing it wrong. At least, I also felt one of the hens' crops, and they felt exactly the same. Both felt firm and large, but she seems normal and he doesn't. Maybe I'm feeling the wrong area? The only good thing is that he didn't have any foaming or drooling going on this time.
He's back in the basement for the night, with only water because I'm worried about adding more food if there's a crop issue. I can remove the water too, if that's best.
I must be missing something obvious here. Should I treat for an impacted crop, even if I'm not 100% certain that's what it is?