When palying against ezreal he is able to flash out of a singed throw and yesterday he flashed out of a blitzcrank grab. The grab landed and he never pulled in just did an awkward flash further away after the grab landed. This seems like a bug or issue as I thought blitzcrank grab was a suppress until pulled in. Is this working as intended?
Yes. Works the same with a lot of other stuff like Tristana jump.
For added clarification, it's on a cast time(and a very noticeable one at that). These are not interrupted by any form of CC and can only be stopped by outright killing the champion before the cast finishes. Another thing to note, some CC effects will take come into play after it's finished.
An example would be when I use 
' Frozen Tomb on 
just as she jumps. The spell will proc but she'll still continue jumping and be stunned once she lands.
Blitz stuns for the duration it takes to move a target to him.
The way Ezreals dash works is since it has a cast time (time between the player hitting E and Ezreal starting to dash) it allows him to take CC in one place during the cast time, then carry that CC with him as he dashes (a command he set up before the stun). I've jumped while rooted with Jinx's flame chompers before.
I think i saw something very similar to this the other day when a Nautilus hooked a Lee Sin at the very beginning of a ward hop. Nautilus was pulled to where he would have gone, but Lee seemed to be completely unaffected.
