Landorus (BW Promo 79) - Rock Tomb

[joelsoh]

The Defending Pokémon can't retreat during your opponent's next turn.

Seems straight forward, but I'll ask anyhow.

If Landorus were to KO an opponent's Pokémon with Rock Tomb, would the 'unable to retreat' effect still apply to the newly promoted Pokémon?
It doesn't explicitly say the Pokémon that got hit by this attack, right? So I assume, no matter what, they cannot manually retreat.

 

[PokePop]

Actually, it does explicitly say the Pokemon that got hit by the attack.
It is talking about the Defending Pokemon at the moment of the attack.
Which is later KO'd by the damage done from that attack, so it is gone by the time the opponent starts their turn and so their new Defending Pokemon does not have that effect placed upon it.

That's another good thing to help you see how effects work; an effect has to be placed onto something. Usually that is the Defending Pokemon (as in this case). Sometimes it's the attacking Pokemon (for a protective effect, for example), and even once in a while, it is placed on a Player(!), but it has to be placed on something. It's not just a statement to be remembered over the next turn.