You could try going over with her a list of possible explanations for this "operation of error" of holy spirit.
For eg:
a) holy spirit knows this bro better than you
b)holy spirit got it wrong
c) holy spirit is not involved in the appointment of elders.
d)this is an ordinary guy that has been given a promotion by his buddies, not holy spirit
This may help her to think critically, without spooking her too much.