Recently I sold a domain via sedo, which was within 60days lock. They just pulled the domain to their holding account at NetSol. They have a "pull" process at NetSol instead of the regular "push" mechanism
I have not sold a netsol domain through afternic yet but even they should have a holding account at Netsol. Once they take possession of the domain, they ask buyer to open a new account and push the domain to that account. If instead, the buyer insists for the registrar of his own choice then he is asked to wait for the lock period to be over.
So to answer your question - yes, the domain that was already transferred from one account to another can still be sold. It can be transferred away to another registrar within the 60 days of its registration though.