Oh I'm not assuming that insult = duel, just that 'you assumed a throne 'x' years ago = reason for a duel today.
But to declare a duel the person must feel wronged - rightly or not - otherwise its just a fight. So you have an 'insult', then a period to consider, then the seconds (of one sort or another) suggest an apology which both can live with, it only goes to an actual duel (first blood, wound, etc) if they both insist on fighting.
It likely should have gone 'ser estaban is who??? sh*t! Ahem, grits teeth, perhaps I mis-spoke...' crawl woman - eat your pride and have everyone laugh... Now that would have been victory for the baron - and all without a drop of blood shed.
So if as you suggest the Aegis was called stuffed up pretenders robhan would laugh, the OIT have been obsolete for years - to be insulted by them they'd have to be right which is, of course, impossible
The 'insult' is not an 'insult to honour' it's just words. But if someone publicly derided Haelyn, accused Roele of raping captives, burnt a temple, etc, etc then it would be insult - and by the gods they would beg forgiveness - or it would get bloody. Put simply, somethings cannot just be shrugged off by a man of honour...
The baron cast the first insult - the sword mage responded with one of her own. Now you can say that the baron was honest - in which case it was no insult - the question of
who started it tends to be settled by a 'jury of peers' - or simply the survivors. But a noble
has to respond to a serious insult by someone credible - the baron was the aggressor as his comments were not 'gee, I think you were mean not to let my family take our old place' but were very deliberate provocation to force response - modern people might say 'who threw the first punch', medieval people interpreted aggression as including injury to honour (as do many today outside of lawyers of course). not that 'who started it makes much difference' - who picks where / when / how / what level of injury / etc all depends on the exact codes of the duel in question.
Could the swordmage have ignored the baron? Wrong question, Could she have ignored his comments without losing face? Did the insult disparage her honour in someway? Impugn her right to title? If so then no she couldn't - not and keep any noble honour. Which of course is what the baron/whoever was behind it all wanted.
Now she could have tried deriding him as a nobody, laughing him off as so far beneath her that his words were meaningless - and perhaps pulled it off - but then the fact that her title is not fully recognised is precisely why that wouldn't work - and patience is a virtue because it is rare...
As is was the baron came over as scum, he doesn't even make 'brute' hid behind the green knight, he hoped (rightly) that her honour and pride would be her undoing. How brave and noble of him! Now if he had fought her himself then he'd have had major honour - and won regardless of the outcome by showing such courage - if he was right about her and she uses magic to kill him then she loses what shreds of credibility she has, so she's caught between winning but not smashing him which is tricky - and all the while everyone has heard, and everyone is laughing at her predicament. But no, the baron picked the fight, rammed it through before anyone could intervene, and refused to offer chance for apology,
the honourable man seeing foe outmatched offers them surrender, if they are foolish enough to ignore it (she probably would have) then they can indulge in slaughter.The GN doesn't come off much better, if he'd wanted to fight her brother he should have challenged the brother, if he wanted to fight the swordmage he should have challenged her directly. Big brave knight who plots and schemes to fight someone half his size only on the grounds most favourable to him...
we had heard so much better of him... as it is his madness is going to leave a stain deserved or not -
the knight who slaughters friend and foe alike, who is drunk on blood and death...No, if you are looking for a 'winner' look at who ensorcelled the knight / convinced him that the best way to hurt a belinik thug was to become one himself. Personally I wouldn't put much odds on the baron living out the winter one way or the other.