Sivir Shield x Ignite bug

Was playing fizz when i flash w,q ignite on a low health sivir, she popped her e (spell shield) and it blocked both my ignite and my q. This was extremely game turning as it would have been an amazing pick up for a kill on a assassin like fizz and a high priority kill such as the ad marksman. My only thought is that my q (sea urchin strike) must have hit and the very same exact moment as my ignite. please fix this bug thanks :)