Crippling Blow

[rmm10]

There are several items and spells that have Crippling Blow. Just what does it do?

In Live, it does two ticks of Decrease Attack Spd 50%, Decrease Spell Haste 50%, and 20k damage (40k total). Is this the same for THF?

[shannix]

I think it's a special critical hit that double the damge of your crit.