This is the wrong subforum for that, but generally speaking it's better forum practice to leave your post intact and edit your answer into the post rather than deleting it, because you won't be the last person ever to think there was a problem.
Anyway, the duty finder honors both the Adventurer In Need as it was at the moment you entered the queue, and at the moment that you transferred to the instance. If you queued as healer because it said healer, but it changed to tank before you got in, you still get the bonus because you queued as a healer when it said healer. If you queued as healer when it said tank, but it changed to healer just before your queue popped, you get the bonus because healer was in need when your queue popped.