Cho'Gath Silences Fizz While Using Playful/Trickster

I was playing a game as Fizz against Cho'Gath. I saw him use his yell ability, so i naturally E'd away. While I was mid leap, i took damage and got silenced, which prohibited me from using trickster (the second jump) for a few seconds.

E is supposed to make me un-targetable, so I believe this to be a bug.