got a rejection on an item that had a tiny sliver of a scratch on the top of the disc (ie not the shiny side). Was pretty surprised as it was otherwise in excellent condition and I actually had to squint to see what the sticker was pointing at. Still plays fine of course.
for kicks I emailed Amazon about it and for the first time I got the response "the third party purchaser of used games can reject whatever they want for any reason they choose." Interesting.
Personally if i had the job of "Check and see if this is in **** Condition"
I'd reject people for stupid shit like lack of bacon.