Yeah, just sounds like a little stress to me. Like purple said give him a day or two to get used to the new suroundings and he should come out of it.
I used to have one that would hide when anybody new came close to the tank. He would run under a rock untill they left. If someone he knew came up to the tank, he would rush to the glass to greet them. So despite there potential size, I really find them to be big babys. But I love em!