Yasuo Wind Wall + Quinn's Passive Marking

Some time earlier this week, I was playing Yasuo and it happened twice in the same game, I don't know if its intended, but Quinn would be in ultimate, I would be low health (2-3 bars of health left), she would catch up to me, pop my shield with her ult, use her E, I would use Windwall, and the autoattack immediately after her backflip, would be impervious to my Windwall, go through, and kill me. Like, Golden Arrows, blessed by God himself, made to penetrate any feeble wind placed in their way.

So two times did that occur, and it puzzled me. I figured it's either intended, or buggy. Idk. Test it out yourselves, but it did occur, no lag, no drop in frames, it went through.