First of all, as far as I can figure out, balls are identical to any projectile, and projectiles use the ray casting flag for collision, not the collision flag.
There are 2 ways you can do this:
onProjectileHit> self> setRayCasting> off, then on again a second later
onProjectileHit> self> spawnProjectile> Basketball (with a little downward velocity to make it look realistic), and at the same time onProjectileHit> projectile> delete