I did a watch-through of c2e1 a few months ago so I'm going off my memories of that, but I recall realizing that - during the Circus Performance - Caleb was clapping a little along w/ everyone else during each performance (which in itself felt more to me like he was blending in). . . Until the fire act.
I've seen others mention how still he gets when stuff from his past is brought up, and I forgot if he went fully still here, but it stood out to me that while the others were clapping, impressed, he wasn't clapping at all™