Leblanc Clone Cancels Fizz Ult?

I just recently played as fizz, and for some reason whenever I ulted the leblanc and she got low from my combo, her passive clone activated and instead of the ult following the real leblanc which it was already on, the ult marker moved to her clone instantly and she avoided death. Is this a bug, am I seeing things, or is Leblanc just a really strong Fizz counter in this way.