Blocked IP's on api.mojang.com broke single player

I have recently been playing around on my single player game, and decided to play around with player heads. After a lot of heads, every single player I tried to get a head for was just a steve skin. I did anyone from myself to friends to mojang employee names. Every single time it appeared as a steve skin. I used the command "/give hcherndon 397 1 3

{SkullOwner:"hcherndon"}

" An image of what it looks like has been provided.Thanks, hcherndon

Edited with correct scenario after realizing I typed a few commands wrong.