[phyrrus9]

buyer also sent me a screen shot of this
https://imgur.com/a/9ISsh

its odd that she knows apple order number which i never gave it to her and i just dont want things to get more complicated. she told me she doesnt want any refund or anything she just want me to help her unlock her apple ID.

i just wanna make sure i wont get into any trouble lol

Before you sent them the MacBook, was there anything on it?
This really is between Apple and the buyer. They don’t block Apple IDs from being used on stolen phones, and I doubt they do on Macs.

To clarify, they don't actually block anything that pertains to the phone in the state they get it in, but rather they just blacklist it from being signed with any firmware, making it completely useless if it gets reset, and obsolete in a few months. The whole Apple ID lock is just a gatekeeper on that. They use a shared key system to encrypt a challenge hash and then they use said hash to hide the disk key that is used on the /private/var partition