Poopy W doesn't stop Hecarim E push

I feel that its seems unfair that the fact Poppy W-Steadfast Presence doesn't stop Hecarim E-Devastating Charge knock back. Poppy W would stop the Hecarim E dash but when it does Poppy still get push back as though Hecarim has hit Poppy, also I don't know it look right when i was looking at the replay of my game against Hecarim but it seems that Hecarim E damage still apply to Poppy. I think that Hecarim E needs to be adjust because it also the same as Le Blanc where I would W back to my location and still get hit by Hecarim E from miles away. I think that Hecarim E is a bit unfair and needs to be fix or balance or maybe its just a bug in my games I play.