Did the county actually take possession and title of the property.
But if the county took possession and title, then sold the property that would change my answer.
There would then be three transactions, the first being the foreclosure by the county, which would be treated as a sale for all three brothers offset by DOD adjusted basis.
The second transaction would be the purchase by brother A from the county for $79,000. Off the top of my head I don't think that would be treated as a related party transaction, but I would look into it.
The third transaction would be the final sale by A of $102,000 offset by $79,000 basis.