How is it that listing in eBay Motors at the end be "Out of Stock"?

[procms]

I have noticed lately many listings of used vehicles without a reserve price get bids but upon ending the seller says it is "Out of Stock" and then be relisted in the same format and end up being "Out of Stock" again. I think this is a very unfair practice and something that should not be allowed.

[reallynicestamps]

In most categories, Out Of Stock gets the seller a defect.

I'm not sure is this is true in the Motors category which had several differences.