A valet who didn't play by the rules

My research on deeds of arms and the law of arms has tended to emphasize that legitimate war was supposed to be the monopoly of "men at arms,"  i.e. gentlemen, squires, knights and lords of higher rank, the kind of people who had adequate horses and armor.  A scenario written by Geoffroi de Charny around 1350 certainly implies that a lesser man should not be able to capture a gentleman/man at arms for ransom.  But did these theoretical strictures really constrain battlefield behavior?

Here's a passage that Will McLean has taken from Froissart that suggests otherwise:

They fought hand to hand, and Ernauton de Sainte Colombe, an excellent man at arms, was on the point of being killed by a squire of the country called Guillonet de Salenges, who had pushed him so hard that he was quite out of breath, when I will tell you what happened: Ernauton de Sainte Colombe had a servant (un varlet) who was a spectator of the battle, neither attacking nor attacked by any one; but, seeing his master thus distressed, he ran to him, and, wresting the battle-axe from his hands, said, 'Ernauton, go and sit down: recover yourself: you cannot longer continue the battle.' With this battle-axe he advanced upon the squire, and gave him such a blow on the helmet as made him stagger and almost fall down. Guillonet, smarting from the blow, was very wroth, and made for the servant to strike him with his axe on the head; but the varlet avoided it, and grappling with the squire, who was much fatigued, turned him round, and flung him to the ground under him, when he said, 'I will put you to death, if you do not surrender yourself to my master.' 'And who is thy master?' 'Ernauton de Sainte Colombe, with whom you have been so long engaged.' The squire, finding he had not the advantage, being under the servant, who had his dagger ready to strike, surrendered on condition to deliver himself prisoner within fifteen days, at the castle of Lourde, whether rescued or not. Of such service was this servant to his master; and, I must say, sir John, that there was a superabundance of feats of arms that day performed, and many companions were sworn to surrender themselves at Tarbes and at Lourde.

I wonder if Guillonet showed up at Lourde?

Image:  part of the war band, but not men at arms.