UDUD...
ok thanks for the clarification.....but nothing changes in my opinion.
first, the fact the candidate was unknown to the FTO should be irrelevant. i make it a practice to never discuss a candidates abilities or performance with the CFI prior to a flight test. by all means glean what you can from the students file for comments about his/her flying but i feel it is just possible that a CFI might just say something wittingly or otherwise that might influence my judgement...so i prefer not to discuss the candidate with the CFI before a flight test so as to remain totally impartial. well intentioned as it may be, i do not (as i am sure all examiners feel ) need the opinion of another to help me decide if a candidate should pass or fail. that is a task delegated by the licencing authority , to me.
if it were me, i would ( hurt as your colleague may feel ) do nothing. i consider it is not my place to take up the matter personally. that is a matter for the licencing authority and if as you perhaps imply ' mad_jock' that they (not talking about you CAA here but a licencing authority in general) do nothing...nevertheless, it is a matter for them. i have no powers to do anything except report so its on the record...after that it up to the authority to action or not as they see fit. i would not want to get personally involved.
hope thats of some help.....