Is it allowed to leave feedback without trading ?

**Shayeeda** · 05-07-2013

I received a negative feedback : http://www.ownedcore.com/forums/mmo-...-legit-79.html

from user : http://www.ownedcore.com/forums/memb...25-mmowin.html :

" Feedback for Shayeeda: Negative
Been talking with these guys for like 30 mins but couldnt come to an agreement on the 60day game time card. Has anyone bought 60 day game time card from these guys. They want the gold upfront, then they give you the code but they dont have any kind of guarantee that code is legit. Tried to ask the rep if I could give them half of the gold first, the the other half after I made sure the code was working and legit. The rep refused which makes it rather shady. "

As you can see, the trade didn't happen and he left the feedback just because he felt it was "shady".
I think what makes it shady here is that he's a new member without any reputation ,on the other hand ,we are a verified member,donator who's been a trusted since 2009.
But let's put aside why it didn't happen. Is it allowed or right to leave a feedback without having done trades ?

If it's right ,does that mean I can leave a negative feedback just because agreement can't been met or not in your favor ? or I can leave a positive feedback because we had a good conversation and he makes me happy ? It's not fair .
If it's wrong ,what can we do about it ? You can't change your feedback when it's done !

Have been trying to get answers from the moderators but they seem to be busy or choose to ignore .
Maybe you guys can give me some ideas ..thanks for your attention =)