Fiora's Riposte canceling spells instead of stopping damage

Hello All, Haven't posted in the new forums but wanted to share this bug as it seemed severe and not intended from what I can research. The bug is as follows.

[Live] Gameplay: Fiora Kit: When a user casts a spell that will do damage over time, Fiora's Riposte cancels the spell entirely, instead of stopping damage for just those .75 secs.

Description: When a user casts a spell that will last longer than riposte's duration, Riposte cancels the spell entirely instead of stopping damage for those .75 secs. The most noticeable spells this happened with (and where i first noticed it) was with Ignite and Malzahar's Malefic Visions. Both ignite and visions have a longer duration then riposte, however when riposte finishes, the spell will not be active, instead it will be ignored entirely, working more like an invulnerable spell shield, instead of just stopping damage for that .75 secs. When the ignite was cast during riposte the particle effects did not appear, no damage was dealt (Even after riposte's duration ended) and grievous wounds was not applied. The same happened with malefic visions, no particle effects appeared, and no damage is done after riposte's initial .75 secs. I have seen this happen in two games now, however only with ignite and malefic visions, but it would seem to happen with any DOT that extends past riposte's .75 sec duration.

Steps:

1. Start a game of League with Fiora and Malzahar present (have ignite on malzahar)
2. Enter into game and approach each other.
3. Have fiora prepare to cast riposte and Malzahar prepare to ignite.
4. The split second after fiora casts riposte cast ignite.
5. Notice ignite is completely canceled with no effects shown in game and even after riposte is done no damage from the 5 seconds of ignite occurs.

If you need any more information please feel free to respond. I will try to grab a video of it if i can.