Playing Offline on a World Will Create Another Player.DAT in The World Files

If you log into a world online with a Mojang account, it creates a Player.dat (Player being your username) and if you log in offline it will create another player.dat (player this time being your email address) Here is a link to my world's player foldier https://www.dropbox.com/sh/yrv1z5gzkl6ne59/oQt512LPiS