setResult does not work when BACK button pressed

Question

I am trying to setResult after the BACK button was pressed. I call in onDestroy

Intent data = new Intent();
setResult(RESULT_OK, data) 

But

Answer 1

Don't rely on any logic executed in onPause of one activity when you return to the initial one. According to the docs:

Implementations of this method (onPause) must be very quick because the next activity will not be resumed until this method returns

See http://goo.gl/8S2Y for details.

The safest way is to set result after each result altering operation is complete (as you mention in your answer)