Thanks you very much, friends. Some time someone suggested the Scots would shout their chieftain's name after a victory, so MacAuley could very well be some sort of MAc-Walli(s) or even MacCollough. It was this 'revenge' in the subtitles that had puzzled me.
Of course, Hollywood follows that principle: 'you can rape History but only to beget a child'.
Thanks again.