I bought an iPhone 5s and gifted it to a friend abroad without opening it and activating it. I was wondering if it's possible for that friend to unlock the iPhone without having to activate it with the original carrier sim card since he doesn't have that sim, and can't get it in his country.
No. A factory unlock feeds the unlock status to the collective database that iTunes or the device polls when it does the activation.
Once the carrier has confirmed unlock status (or Apple feeds the unlock status to the carriers when you buy an iPhone factory unlocked out of the box) - the next restore event will alert you that the device is now unlocked.
In the case of a third party unlock - again, as long as the device sees that it is whitelisted when activation time happens, it doesn't matter who caused your phone's device ID to be cleared - just that it matches perfectly for the unlock to succeed.
I have been battling for two months now on this problem.
I bought an iPhone from someone in the United States, I am in South Africa - but he sent it to me without the original SIM-card. There is nothing I can do - I have called ATT and they say that the only way I can unlock the phone is if I have the original SIM.
I have confirmation that the phone is 'whitelisted'. I have the email saying all the "congratulations" etc., but the 3rd bullet says
This really really sucks. Oh and one more thing - because I am not the original owner they will not give me a solution or further details.