Well it depends... if you mean after the set was won by someone then no it won't. However, everything that happens between map start and the score hitting 3 for one of the teams in a live set counts. So if you tk'd someone after winning the first or second round, for example, then it would count. Or, if you did mean tking after the last round in a set, then you probably found yourself in a very unlucky scenario where the tk happened so soon after the round was won that it just happened to be logged before the round result did.