The Municipal Dunny Man
Whatever information or instruction received over radio by the crew of an operating flight need not be acted upon by the captain if he can reasonably justify contrary choices. Where any instruction is received twice from an unidentified source, there exists substantial doubt about the authenticity when a callsign is reluctantly given on the third call.
If I had extreme doubt about the correct action, I might take some notice of information, regardless of the origin. Where the selected action is more obvious, It would be completely reasonable to ignore the particular calls as being just pure crap.
I am baffled about the sanity of company management who are sure going to be held to account!. I am reminded of a song:
"The municipal dunny dump was full up to the brim ..... The municipal dunny man fell in and couldn't swim ... And as he sank beneath the foam, you could hear the maggots cry .... There ain't no place like home" etc etc
Management seem a lot like this this bloke.