Roost?

[freaktron]

I was playing in Diamond the other day when I was surfing above Sunyshore, when this happened:

Torterra used Crunch!

The wild Pelipper used Roost!
The wild Pelipper regained health!

I thought Roost's "no Flying" effect stays in effect next turn, so...

Torterra used Earthquake!
It doesn't affect the wild Pelipper...

Roost: In addition to healing 50% health, the user, if Flying-type, loses the resistances, immunities, and vulnerabilities of the Flying-type - that is, it can be hit by Ground attacks and is not weak to Ice\Electric\Rock or resistant to Grass\Bug\Fighting. Pokemon with Levitate are not affected. If a Flying-type user has a secondary type, like Zapdos' Electric type, they still retain that type.

This applies for the rest of the turn after Roost has been used.

So...i'm confused here. By that I thought it meant:

Turn 1:
Foe uses Roost

Turn 2:
Foe is not Flying-type
I use Earthquake and the foe is vulnerable.
Foe is now Flying-type again.

What gives? Shouldn't Pelipper have lost its Flying-type that turn and have been vulnerable to EQ?

 

[EBCubs03]

1 turn only.

 

[Mario With Lasers]

It only lasts until the end of the turn Roost is used.

 

[wDro]

So it is better to use roost last then?

 

[Seph]

So it is better to use roost last then?

Obviously if they can EQ you. If you can go first you can do things like make skarmory resitant to rock vs stone edging rhyperior.