Clicking back after uploading file then clicking to login again results in 404 error

This is slightly odd behaviour from a user's perspective but I did this:

1. Logged in.
2. Uploaded file.
3. Clicked browser back button.
4. Clicked on Google login credentials again.
5. Got 404 page trying to access: http://ec2-54-73-99-234.eu-west-1.compute.amazonaws.com/me

I used Safari and Chrome. Happy to re-produce!