Limon, Jerzy. "Rehabilitating Tybalt: A New Interpretation of
the Duel Scene in Romeo and Juliet."Shakespeare's Romeo and Juliet: Texts, Contexts, and Interpretation. Ed. Jay L. Halio. Newark: U of Delaware P, 1995. 97-106.

Thesis: Tybalt kills Mercutio with a thrust under Romeo's arm, then runs away, but Limon asks us to believe that Tybalt is an honorable man. Here is Limon's account of how Mercutio received his death wound:

It seems not improbable that this is what happened: let us imagine that Tybalt strikes in order to hit Mercutio, when suddenly, as if from below the ground, Romeo appears before him. Fortunately Tybalt is an excellent swordsman and always a man of honor: although it is Romeo who was to have been his victim, it was forbidden to even so much as scratch a third person (the one not taking part in the duel), so at the last moment he changes the direction of the thrust (which cannot now simply "hang in the air") and buries the blade into the open space between the trunk and arm of Romeo. And then he feels something that he did not foresee or intend: the blade strikes flesh. It is a mistake to conclude that Tybalt profited by Mercutio's temporary inattention and treacherously dealt him a thrust from under Romeo's arm while he was not looking. That would have been a dishonorable act, inconsistent with binding principles.   (103)
This mistake, according to Limon, is Tybalt's motivation for running away:
Thus when Tybalt, who does not want to injure Romeo, changes the direction of his thrust and strikes the unsuspecting Mercutio, he immediately realizes what has happened. He -- almost oversensitive in matters of honor -- has committed a shameful act, unworthy of gentleman. Chance imprints a stain on his honor and that of his family. This is what terrifies him; this is why he loses his head and reacts in a manner that is natural at such times -- he runs away.    (104)

It is Tybalt's sense of honor, Limon, says, which brings Tybalt back:

There can be no doubt that Tybalt fully realized that his sudden flight from the field of battle would be attributed to cowardice. So he comes back to wipe away the disgrace that, in his eyes, covers the good name of his family. The outcome of the duel, from this point of view, no longer has much significance since in the eyes of the citizens he would always remain compromised . . . . For him, it is vital that he return. He is psychologically very far from a state of equilibrium, and it is perhaps for this reason that -- shaken, enraged, and "mad" -- he succumbs in the duel.   (104)
Evaluation: Because Shakespeare doesn't explain either Tybalt's running away or his return, Limon's theories can't be supported from the text. On the other hand, his ideas could be very useful for the actor playing Tybalt, since they give Tybalt a consistent motivation. However, it's hard to see what difference Tybalt's motivation makes in the general pattern of the play. If Tybalt is a cowardly punk who kills Mercutio with a lucky stroke, Romeo is the victim of chance, and if Tybalt is an honorable man who makes a mistake, Romeo is still the victim of chance.

Bottom Line: Interesting.