These abilities Heroic Strike/Cleave are not being cancelled with /stopcasting.
What happens when you use /stopcasting while Heroic Strike is being queued it only cancel the animation but Heroic Strike is still being cast(it does damage and uses rage) despite the fact it should have been cancelled by using /stopcasting.
retail proof:
http://www.arenajunkies.com/topic/12...-strike-macro/