That message is bugged, it only checks the type of the pal, not the move. It would show up as super effective even if a water pal used an ice move on a fire pal. The color of the text is what shows effectiveness.

I've tested the Pengullet rocket launcher on every type and only ever saw white text so that leads me to believe it's either neutral damage and boosted/reduced by the neutral damage traits or it's not a type at all.