I agree that the buyer was "made whole" by being almost immediately refunded. The seller, if s/he knows what they're doing and is being transparent/honest, looked for the book for a fair amount of time and couldn't find it.
I get that around here 'not getting the comic but getting refunded' isn't exact the same concept, because you could be getting a unique product, and/or great deal. The seller has offered to sell it at the same price if found. Will it be found? Is it a tactic to retain credibility? We'll never know. I guess we have to take it at face value, though, right?
I agree that this seems like an incident that should avoid the Probation List, and should be filed under the 'personal list'. The seller fumbled.