[Gameplay] Master Yi Q spell = block

I was in a game when i was running cause a dangerous Master Yi run after me! He press Q to dash on me and kill me but he block me in the walll and i cant move. how to escape : waste Flash... This arrived to me 2 time, 1 time in normal and but this time it was in ranked, this can ruin game by killing you.

How to do this bug

1. Take master yi and an other champ.
2. Put the champ on a wall.
3. Use Q with Yi ( I think its luck cause this can arrive or not ).