Conflicting but Interesting Confirmation Dialog of Firefox on Ubuntu

Conflicting but Interesting Confirmation Dialog of Firefox on Ubuntu

I just observed a conflicting but an interesting confirmation dialog of Firefox on Ubuntu. The two points to note over there are:

1. Unlike Windows, The 'Cancel' button comes before 'OK' button.
   
2. Though the cancel button precedes the OK button the precedence or the default button behavior is still retained by OK button only.