He is absolutely "scared", he is hiding something or does not want to answer LE's questions. "Gimme Immunity!!.
Also, maybe the best reason is for self protection. Remember, "from day one", KC has been pointing the blame around. CA has done more than her share, of placing blame on innocent people, for Ex: Zanny, Amy, Jesse, Tony and the list goes on and on. Do you think Momma wouldn't throw son Lee under the bus to save KC? I believe they (CA & GA and LA) have somewhat parted ways, as LA became quite scarse a few months ago.
O/T What pissed me off, well, one of the things, is LA rudely removing the flowers, teddy bears and memorial made to Caylee out of love and concern.
I hate to say one thing and I hope you'll all understand why I'm saying it. Brother had a "moment" with that memorial, no doubt. People do make mistakes. He, like his father, is trying to protect his mother. The men in this family do tend to do that and have a pattern for such behavior in what's been reported to LE.
IMO, I'd urge those who haven't reviewed LA's statement transcript to police to do so again. Between he and his father, away from the grandmother, they were most cooperative with LE. I have included both links below - I think, IMO, it's most important not to forget what they tried to do away from the eyes of the matriarch in that family.
http://www.cfnews13.com/uploadedFiles/georgeanthony july24.pdf
http://www.cfnews13.com/uploadedFiles/01 Lee Anthony July 29, 2008.pdf