unrecognized flags reported, but execution continues anyway

[ninedotnine]

Somewhat dangerous behaviour, incompatible with GNU rm:

» touch a b c
» ls
a  b  c
» rm -z a b
rm: invalid option -- 'z'
Try 'rm --help' for more information.
» ls
a  b  c
» trash -z a b
trash: Unrecognized option -z
» ls
c
»