If he was so smart and prescient, then why were AF Mystic Crusaders able to steal it from his Lake Louise lair in the first place?

Hell, how did they even know to steal it?

They knew he'd been stockpiling orichalcum and wanted to buy it. When that failed they in runners/spec ops.

They succeeded b/c A) dramatic license B) A dragon's lair isn't as much of a threat when the dragon's not in it or C) some combination of the A and B.