You did sell the tickets elsewhere though.

You sold them back to the seller so the feedback does NOT lie.

Also I see you left a neg feedback as the seller would not post to a different address.

Sellers should ONLY post to the address on the paypal payment for their protection so your feedback left is not honest as you did not state they would not post to an address other than the one they were told to post to by paypal

Why should that seller risk the sale and a claim of item not received??

So where is the difference really???

Also you have violated ebays policies by

a) not sending an item that was paid for and reneging on the sale

b) You left a false +ive for the buyer that is also a policy violation and hope the buyer reports it and it will be removed and you will get a policy violation recorded against you.