Stance of the clone was different on each attempt while Kahn's leg swept from screen side both times on the video in the post I'm commenting on.
The first time, the ice clone's extended leg was toward the background side of the screen while Kahn's leg come from the foreground side of the screen avoiding that leg entirely, and Kahn's leg isn't fully extended while on the same horizontal of the plane that clone's leg is on, avoiding that leg as well, then collides with Sub's right leg. The second time, the ice clone's extended leg was toward the foreground side of the screen, which Kahn's leg collided with as it was also coming from the foreground side of the screen. Watch the video on youtube at .25x speed and see what I'm talking about.
Confirmed, the game has 3D hit/hurtboxes so if the 3D attack animations don't cause the model's hurtbox to collide with the hitbox of the ice clone's 3D model then it will "go through the attack" because the collision never occurred. And since we can't see the models from another angle, we can't see that the models don't collide; they probably go between the legs, to either side the head, or around the abdomen because he has a slender profile when he twists to the side while he jumps back to create the ice clone.
So if this is an unintended result of the games hit/hurtbox mechanics, they can increase the width of the ice clone's hitbox, creating a phatom hitbox that will act like a wall along that horizontal to fix it; however, if it's by design then it's just something that Subs will have to deal with.