Long answer for the miss: in a fight in such close quarters, it's actually not too unrealistic for there to be a miss, thanks to the high tension of the situation and the distracted nature of the fighter. Plus, he doesn't actually want to hurt his friend, meaning he's holding back on some level. Furthermore, he's up against a (presumably) incredibly skilled opponent, who isn't fighting in the way he would (presumably) have familiarity with, rendering his normal attack patterns less effective.
...Or, y'know...because it's convenient to the plot. :P
Long answer for the miss: in a fight in such close quarters, it's actually not too unrealistic for there to be a miss, thanks to the high tension of the situation and the distracted nature of the fighter. Plus, he doesn't actually want to hurt his friend, meaning he's holding back on some level. Furthermore, he's up against a (presumably) incredibly skilled opponent, who isn't fighting in the way he would (presumably) have familiarity with, rendering his normal attack patterns less effective.
...Or, y'know...because it's convenient to the plot. :P