If ASR did not feel the depth of emotion he displayed while breaking up, he would have not broken up at the first place. He was Arnav that time, right from the moment kushi was in distress. The way La requested, he simply couldn't resist hugging her out of guilt ! He realized how much he has wronged her. Also if you could see how soft he was with her before, ots not surprising.
With Kushi its a different ball game for Arnav.
851