Very nice. This combo works because he was frozen and got hit by the uppercut at the exact same time, I'm guessing instead of counting it as 1 hit, it counted it as zero hits because the clone wouldn't be a hit, and in all other double hit scenarios, it counts as one hit, ie: Jade Return Boomerang + any hit. It's not like the scream which has some broken built in properties. Never suspected this however but it makes sense.
I think you could max this combo out to HPHPHP, JK, JK, HK at the end which would add about 12% to the combo for damage sake.
Ded_ was telling me about that. He's done it with some other specials like sektors homing missile. Uppercut+smart missle, no damage readout (which means it only registered as 1 hit). This is also why you can connect 5 forceballs at one time and none of them will be damage protected making 60%+ damage. Then after that you can do aaHPHP, forceball (it's just now locks), and now finish the combo with dashes or whatever. Exactly like from RZP's vid, Devastation 2.