Even though he didnt get a proper reply from her, he was relieved of the fact that there is nothing going in between Dushyanth and Gulaal as he feared and he trust Gulaal more than anything and so he believes that there will be a strong reason for her to hide the truth.
I think after solving this Kesar-Gulaal problems, they might bring Vasanths murder mystery in to play. An important thing is if the case is brought up then everyone will accuse Gulaal for hiding the truth and at that time only kesar will be there to support and save Gulaal from the possible situation and for that first of all they have to resolve the tension between Kesar and Gulaal or other wise it wont work in the proper way.