Series 3 Nike Activation Lock Help

[NCEE2016]

My friend has an apple watch series 3 that was paired with his phone and it worked great for a year. He got water damage on the phone and took it to apple. Apple gave him a new phone. It eventually stopped pairing. He puts the email and password in for activation lock and nothing happens, it just times out and never pairs correctly.

He also claims that the email listed on the activation lock page is not his

Is this something Apple may have done inadvertently after giving him the new phone and not unpairing it properly?
Any insight on the matter would be helpful.

Thanks