should your first reply to this not be "you told her Gold, but she immediately turned you away without asking to see it ?"

Who knows, this could be this passengers first time flying with a gold card, when do I show it, to this person, or at the check-in desk ? I think I'm allowed to use this queue, but really I'm not sure, surely this employee will confirm if I am or not.

Querying the actions of a paying passenger who may or may not know the exact protocol, rather than querying the reaction of an employee who is PAID to know the protocol, is a rather perverse way of looking at the scenario.