How many times have we done something, gotten angry at something, realized we were wrong, but have gone on to do the same mistake again. Life is a learning process, and bad habbits are hard to break, specially bad thinking habbits.
RK is a very rash, insecure, and weak person. Although today we saw him realize he was wrong in what he did to Madhu, at another event's encounter (his car's windshield being broken), he went right back to being the same angry, rash, weak person. I am glad, the writer did not choose to make a complete change in RK. It is my hope that RK will see his mistake again, realize, and try again to be better to Madhu. He will succeed in some places, fail in others. But his love will give him the strength to keep trying, and with enough practice, he will eventually become a strong-consistent character.