The moderators are careful to remove images with names and emails from people who haven't granted permission.
When I start to type a name like Sanjay, I start "Sanj" and thenI get suggestions of several Sanjay's I know. That makes sense to me. Photos is trying to help me out and keep from forcing me to type the whole name. I appreciate that. It gets the list of possibilities anywhere it can. The first one may be a name it finds in the list of Person albums, names you have used before to tag with. But there may be another Sanjay it could be, so it hunts through your contacts list, emails, and who knows what else. That's pretty cool. Unless you always mean the same "Sanjay."
Probably the first one is the one you mean. Like léonie said, if you sometimes pick one and sometimes the other, you'll end up with two Person albums for the same friend. So just always use the same one, and you're good. (Sometimes I screw up, and I have to go to the Person folder and combine a couple of albums. It happens...)