I take Shotokan Karate and a friend of mine is a black belt in TKD. We practice and spar togethor sometimes.
It surprised me at first until he explained... Because aside from the occassional advanced kick he fought very similarly to myself. When you get a very traditional TKD guy its nothing like what you see in the olympics and the commercialized stuff.
It all comes down to the teacher and how skilled the fighter is. The style isn't that important. Personally...I'm obviously biased... but I think Karate is a better system because it is more well rounded, where TKD puts an emphasis on kicks. My friend agree's, but he's good enough to know better than to kick crazy all the time.... its all about the individual.
It depends on these factors
-agression
-experienced
-skill
-environment
-rule(whose rule karate competitio rule or taekwondo competition rule)
-size(not total matter but still has some affect)
This can't be determined, because we don't know the skills of the fighters. Both styles are good, but some times it comes down to who was able to inflict more damage. It's not the style, it's the fighter and how well trained they. Skills, son, skills!