jQuery.ajax beforeSend callback is not returning the right result

I understand that jQuery.ajax provides "beforeSend" callback. If this callback returns false then entire request is cancelled.

I verified that here http://jsfiddle.net/neerajdotname/9dBRY/10/ .

However take a look at slightly modified version http://jsfiddle.net/neerajdotname/sLnY8/6/

In this case beforeSend callback is triggering a previous开发者_JAVA百科ly registered event. The returned value of that trigger is used to determine if request should be cancelled or not.

As you can see I am returning false from triggered call. However that returned value is not equal to false.