If I bought you a cat and gave it to you would it still be my cat? No because I gave it to you.
It's different with a key though.
If he just emails Badspot the authentication saying he wants the key deactivated then it can be done because he has the auth.
He payed for it. <- HE bought first (his)
Gave to Glass. <- Ownership could be Glass or Darkness but he bought it first.
Either way it doesn't matter.
If darkness wants the key deactivated it can happen very
very easily.
I just recommend getting a new key before he and Glass get in trouble for key sharing.
If Badspot gets suspicious he might just deactivate it himself just because.