The sheriff sounds like an old school sheriff dealing with a hard core drunk, he knew what he was dealing with and kept trying to take the guy home so that he could sleep it off, just routine business.
Today the average cop would internalize it and be having emotional responses (possibly vengeful and violent) to the raving and rambling, rather than being amused by a drunk guy.
Plenty of old school sheriffs are dead from drunks because the played them short.