Scrutiny isn't a green dragon though
And no, if you dps Trakanon, you don't have a higher chance at getting the green dragon head, because the green dragon is an interrupt + 2 sec stifle on beneficial spells. Now of course there's other reactive debuffs...
If you wanna know more (which you really should if you wanna be at your best for Trak), I'm pretty sure you can find the whole Trakanon strat somewhere on Flames (or read your guild forums imo!

), unless it's been removed? Who knows...