No, you can't challenge their findings. This is subjective and you may not completely agree but they will have standards to check.
'Good' indicates light wear and generally very nice condition.
I haven't seen the bracelet, but, if it is the one you sold this month, the photos show significant scratches near to the clasp and further scratches on several of the links so it seems their assessment is accurate. 'Visible flaws' also indicates 'fair', rather than 'good' condition.
You can relist it, and may even sell to the same buyer, but you should change the condition from 'good' to 'fair'.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)