Bug in 'file' command on 10.5.8? (Or am I doin' it wrong?)
On my copy of Mac OS X 10.5.8, I see the same behaviour as you. file somelink and file -L somelink have the same, --dereference behaviour, regardless of the presence or absence of an environment variable POSIXLY_CORRECT. file -h somelink has the --no-dereference behaviour.