Comment 98 for bug 60995

Isn't the solution to the accidental data loss problem to keep form data in history? If you accidentally pressed back when filling out a form, you could press forward to return without losing form data. Actions should be reversible, regardless of whether you press backspace or the back button.

I agree that the user might be surprised after pressing the back button if focus wasn't on a text field, but the user should be able to reverse that action by pressing forward with no data loss.