I just started testing out the newest Snapshot of Minecraft, and I discovered, that you can look through walls using second or thrid person view and some snow. I don't have any mods/texturepacks on, just to be clear. You can see me using this glitch in the attached file below. I hope this helps to fix the bug! (Here is the link to the Video: https://www.youtube.com/watch?v=Jeiv3ErBtBE )