Trust me it is possible,where I work I drive a work truck throughout the day and have some not so desirable people riding in the back and at times I know I have seen them eyeballing my pass code entry so I switch pass code quite often and have actually forgot it a few times but luckily I alternate between the same passwords and codes so I always figure it out.
Now know that I'm not taking up for this guy and YES this is a very very fishy situation like I said its possible it's just their wording is suspicious because trust me if I got locked out of my phone I would be at the apple store in a second but luckily I'm buying more and more NEW devices and it's a good thing because the last ipad and iPhone i purchased both had activation lock but thank goodness they were both legitimate and the actual owners removed them from iCloud for me.
In fairness I agree that it IS possible. The problem is, in those instances where it is, there is no way to convince people who really know the seriousness of the Apple theft problem that it's NOT a scam, so they'd be MUCH better off just contacting Apple directly.
I truly hope the OP was legit, but the odds are that he/she bought a phone (or stole one), that was password locked and is trying to fix it by claiming they "forgot" the password. Maybe it's wrong. Maybe everything on the internet is true! It could happen... And I could be Bob Hope. You never know, which is why on the internet you have to go with what is most likely the truth, and the sad reality is it's most likely stolen.
It is what it is