iCloud sending reset mail to iCloud address.

Hi, I did setup my father-in-law's iphone 5 years ago, and since I have never logged in to his Apple ID (the one I made), nor had he, I lost the password.

However, when I try to reset the password the iCloud is sending an email to the same address I am trying to reset, is this normal? or is it a bug in icloud server? I basically shouldn't be able to make such an account since I know that it is impossible to make an Apple ID with icloud.com address, but now his iphone is connected to an icloud.com address ID and the recovery email is an icloud.com address too.

Anyway to find a solution for such a loophole without resetting the phone and setting up another apple ID?

Thanks.