Why is someone allowed to leave negative feedback after they have lost a case against you?

[raycarp.0646]

I had a situation where a buyer claimed they had not received an item and raised a case against me, claiming that they had received a damaged envelope. I send them video proof of the item being posted and they admitted that I was not at fault and lost their case ( the way the coin was enclosed in cardboard in the envelope meant it was impossible for accidental loss ).  They would not provide evidence for me to claim from Royal Mail and refused to claim themselves. 

They've been allowed to leave negative feedback for me but I can't now leave negative feedback for them to warn other sellers about the theft that took place.

[collectorsparadise_2]

Hi unless you have a tracking number royal mail wont sort a claim

if you sent it recordered you can print out a claims form from their website

I send everything from all my accounts recorded now or print ebay lables that are trackable if its low value stuff . if high value stick with royal mail

I had a chap keep the expensive contents and send me back an embty box recordered I had to get the police involved as ebay said it had been returned

also be on the lookout for scamers with 0 feedback making offers, they are getting more frequent

I had one today asking to text them or email about an item ,always look at their feedback it will tell you when the account was opened let the offer run , dont even decline it

if your ever unsure google the telephone number