I cannot think that Writers would make Abhi a suspect..since now-a-days they also know that audiences have matured ..so they know that they will suspect either Ranjeet or Abhi ..so mostly it wont it Abhi ..
also as per last shot Piya was filled with mud and Kakika heard someone who was washing his face I guess..so if it is Abhi ..then his clothes should have been spoiled..but it did not seem like that ..
But again you never know for the twist in the story they might show its Abhi..
Also looking at the lenght of his role which says 3-4 months ..I think they might show him going to jail or something like that ..and just remove his charachter