Almost killed the Red dragon once with the Lore card Terrified, I think the name is. Rolled two Flag/Lore (22% chance) and it had to retreat six hexes. Could not retreat for three of them, so I got three hits/two critical. Could not pull off the kill though (31%). It had my opponent sweating though.
As an aside, I generally ignore the dragon as much as possible and just try to play my own game. Where I will deviate from that is when I have weapons or Lore that force retreats. Given the long retreats of the dragons, if you stack enough of them up you could get a really powerful critical roll. So, I've used Bagpipers with Darken the Sky (and Take Aim or Eagle Eye should also work well) or the Terrified Lore card. As each additional "hit" adds three hits and converts to two or three critical rolls, it seems like the most probably way to attack them.
I laugh at the thought that you would drive off a dragon with a dwarf playing the bagpipes. Would have made a hell of a story if it had worked when I tried it three times (twice with Darken the Skies) against Joe Fling...