[gameplay] Illaoi missing tentacle indicator

Was playing as Ryze vs Illaoi, she caught me with her soul hook thing, and i was slowed and running away trying to dodge her tentacles. A tentacle spawned on my turret, and i had my finger on the flash button to see if i would need to flash out of the tentacle smash-down. But alas, the indicator never came. just a soul-crushing tentacle that sent my to my fountainous grave. I was confused because the last time it smashed down on me (from getting soulgrabbed or whatever) there WAS an indicator, and sure enough, the next time there was too, leading me to believe it was in fact a bug.