Ah, League of Legends interactions. A genre of study in its own right, really. One never knows which update will make the whole game unravel, and we love it.
Picture this. You've just had a two versus two fight bot lane, in which you've killed the enemy support and are now retreating away from the enemy ADC, which just happens to be Caitlyn. Caitlyn uses her ultimate on one of you, and, to stop it, your ally fears her.
However, not only does fear not stop Caitlyn's ult while it is being channeled, it allows it to be used again five seconds after the first Ace in the Hole has been fired.
Now, Caitlyn's ultimate ability is an annoying one, to be sure, but it most definitely isn't game-breaking. It cannot turn around a team fight, and it can only target one champion at a time. What this does imply, however, is that League of Legends animations are taking precedence over some, perhaps soon all, forms of cc.
This phenomenon has been present in the game even before, with Pyke's ultimate, for example, always going through if the cc comes a bit late, but this Caitlyn bug is a new development.
Hopefully, we will not see this as a repeating trend, one in which crowd control abilities get countered by champion animations just having too much priority in the interaction. Especially since a lot of League of Legends abilities can only be reacted upon, and not proactively stopped.