It was in a random match up battle my conkeldur was holding a big root and I used drain punch on skarmory and then the super effective noise was heard but it did the same amount of damage as if it wasn't a SE hit. I dunno what happen and I dunno what the skarmory was holding. And I dunno if it was a glitch.
That's probably because Skarmory previously used Roost on that turn, which removes its Flying type for that turn.
Well, I am unsure of what is being asked, but if the Skarmory used Roost then it would loose it's flying typing for that turn, meaning Drain Punch would hit it super effectively for that turn.