Blitzcrank's E cancels Fizz's E invulnerbility prematurely [GAMEPLAY]

It happened to me twice, and it seems to be 100% replicable just by doing the following: Fizz E:s whenever Blitzcrank has used E and targets Fizz right before he jumps. I do not know if this is intended or not, but it seems very strange, as it happens WHEN he is untargetable? Here is another Link https://www.youtube.com/watch?v=UjndG-NFpYc&feature=youtu.be