Hiccup grit his teeth as the comment hit home. But he wasn't going to wallow over it, not while there was still a chance that Dipper could be saved. The guilt could wait until later, when they weren't fighting for their lives. For now, he was going to paper over it with sarcasm.

"Dipper, do me a favor? Tell the Faceless if they want to insult me, they'd should do it in person instead of hiding behind you."

With that Toothless turned a corner, and ran right into a dead-end.