Unfortunately, many sellers are human beings.
Our lizard overlords will have to do something about this Real Soon Now.
Your seller made a mistake.
He did not close all his eBay listings when he went away for an extended period. If he had a Store, he could have put the lisitngs On Vacation, and they would not have been available for sale. Without a Store, he could close all his lisitings for the period he was away and reopen them up to 90 days later.
Since he had the poor judgement to leave the listings open, he should have either had a trusted person to complete any sales, which should have been relatively easy if he had a B&M shop operating while he was away. Or he should have been checking his eBay account regularly and communicating with any customers.
But fraud? Nope.
You can still leave feedback if you think it necessary.