Pages like firefox/features are relying on native HTML5 form validation. Older browsers (such as IE8 etc) won't get this, and clicking submit with an empty form will still fire the event.

Re: the timeout - we have found that when tracking a GA event before submitting a form (or moving off a page in general), you need to use a `setTimeout` to allow the GA event some time to register. If not, events may not get tracked accurately. Part of bug 877849 is to assess the minimum amount of time needed for this.