IIRC the notes to Bird with the Herd (live recording made in Kansas City) say that he always cleaned up when going to visit his mother, as on this occasion, which results in his being on brilliant form. (Yes, he's on brilliant form - can't vouch for the rest.)
The only recordings when he obviously isn't in full possession of his faculties are the 1946 "Lover Man" session and, to a lesser extent, Charlie Parker Plays Cole Porter, when he had a very short time left to live.