This question is addressed to ooitzoo and any others who feel like Arden should reimburse opgenorf for shipping.
If Arden had shipped his knife at the same time, and still wanted to undo the trade, do you think he still should reimburse opgenorf for shipping as well as pay his own? (Serious question, not sarcasm)
I don't the timing of shipping has anything to do with the situation here. They both dropped the ball in terms of shipping time so its a wash in my book.
The issue is the reasoning behind why AF wanted to ship his knife back; e.g. for reasons other then condition.