…I would not have suffered myself to trouble you with this account of my family afflictions, with a recital which may seem to have been intended to raise myself at the expense of others." (Chapter 31)

I do not think it can be assumed that there are any cordial feelings between Col Brandon and Willoughby because of the bloodless outcome of the duel. Brandon, unlike Willoughby does not abuse his rival, foe, and persecutor because as he says in Chapter 31 he does not wish to “raise” himself at the expense of others; Willoughby of course does not feel this as his behavior in Chapter 10 proves. Willoughby makes it perfectly clear in Chapter 10 that he does not like Col Brandon and at that time can give no supportable reason why he dislikes him to Elinor. IMO Willoughby dislikes Col Brandon because he is envious of his financial independence and because he knows he has wronged him (Eliza) but these are things he cannot admit to Elinor. Willoughby has abused his fifteen year old ward and probably ruined any chance she had of a good marriage in the class, society he has taken pains to establish her in and I think her chances of even making a match in the classes below her are seriously impaired. I think Col Brandon dislikes Willoughby intensely by Chapter 31, his confession—"His character is now before you -- expensive, dissipated, and worse than both. (;D)