Destiny Bond Loophole?

[confused]

I was just watching my friends play Pokemon Cards and we think we might have found a loophole to Gastly' Destiny Bond, but we are not sure if it is valid or not. They ended up playing without the loophole, and both pokemon were knocked out.
Anyways, here's the question... What if Gastly uses Destiny Bond, but the Gastly is poisoned and therefore dies inbetween the turns? The description on Destiny Bond says the opponent is also knocked out if the opponent knocks Gastly during the opponent's turn. The poison would then knock out Gastly inbetween turns. Is this loophole valid?

 

[Jaimes]

Firstly base set gastly is probably (one of) the worst card ever to be written, any other gastly card is worth playing over this. If it uses Destiny Bond, don't attack or just Gust of Wind it away, causing your opponent to waste energy.

Anyway if it was knocked out as the result of poison/burn/a power that places damage, then the opponents Pokemon will not be knocked out as well, as poison/burn/the power is doing so.
The card states 'If a Pokemon Knocks out...' i.e as the result of an attack.