What I expected to happen was...:
You cant enter a container, and be teleported behind yourself.

What actually happened was...:
You can enter a container, and have your head be teleported behind yourself.

Steps to Reproduce:
1. Create a redstone clock and connect it to a command block
2. Put the following command in the command block

tp @p ~ ~ ~ ~ ~3

3. While your head slowly moves downwards, open your inventory or any other container.
4. Your head will continue to move until it's upside down.
(Tested in Singleplayer Creative)