Game-breaking bug with Katarina

So, I'm pushing down mid, and here comes jungle from river. She jumps on me, I QW her, and then we both ult at roughly the exact same time. As mine goes off, she poofs. I end up having to bail, but then I notice that I can no longer Q, nor can I ult. W and E work fine, but my main damage is gone. A few minutes and a restart later, with my stuff still not working, we FF. As soon as the FF goes through, my Q starts working again. I'd almost say the server thought I never stopped ulting, but I'm not sure. Can someone explain a fix to me and/or a cause?