Well in a duel, both use all of their skills, just not cheap skills, such as hiding somewhere and shooting, but exploiting their opponent's weaknesses, and overpowering them. Potions are a cheap way of winning a duel, but in no way did I see Quittaa cheat in that duel, she used her skill (Energy Arrow) to overpower her opponent.
Now, about complaining.
A prearranged, formal combat between two persons, usually fought to settle a point of honor.
A struggle for domination between two contending persons, groups, or ideas.
Those are dictionary definitions. A duel is prearranged, or is simply two people or groups fighting for control. If it is prearranged, (which for example, Shal and Quittaa's duel wasn't, just a fight to see who was better, or for honor, I don't know what it was about exactly), there were no rules layed out, meaning both groups had full right to do whatever they could to win. When Shal complains about that, he is showing that he does not like the fact that a person did something against some kind of rules that were not announced at any time. If you don't want someone to use magic in a duel, say "No magic, etc. allowed" before it starts. Or at least in brackets, if you can't do it IC. That should settle most of it. Now if you want to say something positive and possibly IC after a duel, compliment the person on how strong they are, and say you need to train some more to even be a match for them, or say that it was a close fight, something as long as it isn't whining about losing. Now if that person "cheats" or disobeys the prearranged rules, then you can complain, just don't throw a tantrum. There were no rules setup in that duel (and Shal used potions anyway, so both of them were apperantly "cheating" according to zanzibar's theory) so both parties have no right to complain about what is done.
I said what I had to say, now I'm ignoring this thread, there's no point in continuing.