Twitch ultimate bug

The 31th of May I played a game as fiora vs twitch top. At some point when he had his ultimate available and activated, he tried to hit me while I was under my tower and for some reason I was able to dodge his attacks even though his ultimate attacks are supposed to be empowered AA's.

Unfortunately I can't download the replay anymore since I hadn't recorded it while in-game and the client won't let me download replays from an older patch (7.10).