Chargebacks are not a quick process (at least in my business). It would take well over 1-2 months before the chargeback was completed, and with the volume Amazon likely has to deal with I doubt they are tied to his account already?
That's probably the reason that it's still locked. If he initiated a chargeback, Amazon should put a hold on his account while the entire process gets completed.
Chargebacks are supposed to be a last resort consumer tool, when every other option has been exhausted.
