i thought it was nutz...the pony tail...style of walking...but i cant see why nutz would kill sammy and frame ram...it would be absurd if she is still trying to take revenge of what kartik did and all the mess in her life...
i think they showed suhani also in the same area later so that we get mislead.
other than this one thing of kush running behind someone...the whole episode was imo a filler
also maybe the part where juhi is talking to someone and asking if the work in done...might show that she is planning all this with someone else and using sid as a pawn