His serial starts with XAW, not XAJ.seem like you need to reread
Serials beginning with XAJ4:
Serials between XAJ40000000000 - XAJ40046000000 are safe to buy
Serials between XAJ40046000000 - XAJ40083000000 are possibly patched
Serials above XAJ40083000000 are definitely patched
serial # was XAJ40013487
Serials between XAJ40000000000 - XAJ40046000000 are safe to buy