Shooting Star Dragon Vs. Ally of Justice Catastor

[The Progenitor]

So I feel like this is a pretty common situation for me when I run a quasar deck against a deck that can synchro.  The most recent errata of Catastor has the removed the "destroy that card immediately" text, and its effect can now be chained to once again.

To this point I ask, what happens if Shooting Star Dragon attacks or is attacked by Catastor?  Can Shooting Star Dragon negate Catastor's destruction effect?

I know that the OCG has ruled that Quick Effects cannot activate inside the Damage Step, but I have found nothing of the sort for TCG rulings.  Would the OCG ruling be used in this situation?

[ragda]

If you play in the OCG, sure, use OCG Rulings.
As it stands, SSD can negate and destroy Catastor in the Damage Step when the latter activates.

[oooxp]

catastor doesn't activate on the damage step so I believe that shooting star should work.

[ragda]

Stardust has historically impeded Catastor before because it DOES activate.

At the start of the Damage Step, if this card battles a non-DARK monster: Destroy that monster.

Note the colon, it denotes the end of the activation requirements and the start of (costs, but there aren't any here, then it would have ended with a semicolon to denote the start of) the effect portion. Since it's an effect that activates in the Damage Step, I would say Shooting Star Dragon would also stop it.

[oooxp]

I know the card text says at the start of the damage step, but whenever I think about it carefully, I'm not sure if it is talking about the "damage step" where stat modifying or counter traps can only activate. Otherwise, it could destroy face down monsters which flip at damage step. Again I am very uncertain of this, if you can clarify please do. But I agree Shooting star would activate even if catastor's effect were to activate in the "damage step".

[ragda]

At the start of the Damage Step is when this effect kicks in. Face-down monsters do not have Attributes, and thus do not trigger Catastor. Only after the start of the Damage Step do you flip monsters up for Damage Calculation.