I don't know if anything's spooked him, we share a back yard with 5 other neighbours and there have always been cats/dogs/children/cars in the yard. He's never had any problem with any of them, in fact he comes to the front of his hutch to have a sniff at my cat and next door's Staffy.

He's behaving normally in the hutch, and lets me stroke and cuddle him while he's in there. Nothing has happened while I've been holding him that I'm aware of, he just suddenly seems nervous to be out of his hutch.

He still takes treats from me, so I'm pretty sure it's not me that he's scared of. I'll just have to keep handling him more and give him some extra attention until he's more comfortable.