You could try creating an event type of "dpa_unlock_achievement". See the bottom of the dpa_maybe_unlock_achievement() function in includes/core/functions.php.
I suspect this will end up creating an infinite loop (because awarding an achievement from the "dpa_maybe_unlock_achievement" event will trigger another "dpa_maybe_unlock_achievement" event...) or it will cause the database to be queried twice for the event type. :)
We'll probably need to figure out how to handle this elegantly. In the old Achievements 2.x I had some special handling to stop these situations occurring, but it was so long ago, I can't remember what the exact problem was.