If you have a energy thief unit deployed (say, puppet master), and you deploy another unit within energy thief range (tortun mortar) the visual interaction will trigger, but obviously the puppet master doen't gain AP (as mortar doesn't have any to loss). But, at the next turn, (here is the bug) the tortun mortar receives 1 less AP than he should have gain through his natural AP gain. It's like energy thief can turn the stored AP value of a champion into negative.
