Yeah, but he won the vote of the other dragons to become Loremaster, just after Hestaby was exiled. While we have no idea of the details of that meeting, it may be safe to assume that he had to distance himself at least a little bit. And besides - there's always the chance that he's been infected with Sybil as well. It's all completely wild speculation though, since we have no idea what in the world these dragons think or plot.