If you test this with a human / another controller and it comes up positive then this one slipped past me, but i have done testing and it hasn't ever reset for me, it will be blockable by humans.
The reason the F4 catches and resets is probably because of the hitbox of EX bomb and the position that they are in, the sort of rolling/slamming animation. This is why its hard to time consistantly, because the position of the fall they are in, related to how high they are when you kick them, and what distance from the wall they are at, and at certain heights they will be reset into smoke bomb, other times they will block , and other times it just plain misses!
You cant rely on the AI or training mode, which is dissapointing, so if you can test this with another player, and it resets still, then smoke probably just opened up a new level. Cyrax got nothing on smoke!