Premise: Patrick Maclellan of Bombie (d. c. 1452) Sheriff of Galloway, then the head of his family, the Clan MacLellan, and a staunch royalist declined an invitation to join William Douglas, 8th Earl of Douglas, along with the Earls of Ross and Crawford and Ormond in a powerful alliance against the young King James II of Scotland.
Hypothesis: William is planning on taking action against King James.