When you top, you actually cut the stem. When you FIM, you are really cutting 2/3 of a new set of leaves. This triggers the plant to grow 2 nodes as well as the leaves so youll end up with 3-4 nodes rather than just the 2 you would get from topping. The leaves will be deformed because well, you removed most of it when you FIMed.
Dont forget to FIM the FIM.