Big Prionus californicus' antenna

Description:

I was working on my motorcycle around dusk when I brushed a rose bush and this big beetle took off flying, sounding like "BRAAAAAAAPPP". It was entranced by the headlight and smacked into it, dropping to the ground onto its back where it flailed around a bit. I went inside and got a drinking glass to help him out (since he was so big and the lighting so poor, I wasn't too keen on helping him with fingers since I couldn't identify what kind of bug he was).When I picked him up and got him into better lighting, i could see he wasn't anything fearsome.He was so calm and good-natured, I brought him inside and let him sit on my dining room table to take some pictures. He was a very cooperative subject and just sat there unless I brushed him lightly on the back to guide him somewhere, then he'd walk calmly.When we were done, I set him outside on the half-wall next to my porch and he was gone in the morning.Crazy antenna, no?Positive or negative, please comment!