Hi I am Amisha,
If the spy is shalini or somebody else than Ritu, then the story will come back to square one. Again the triangle between Ritu, Raj, Naina will be there. If Ritu is innocent, then Raj may fall for her which was evident from the expressions he gave when he was in her Room when she cried and hugged him - he felt sorry for her status. Later he was feeling bad for her leaning on sofa in his room when his cell rang.
another thing is that immediately after coming back from Ritu's room, Raj got a call that spy has entered. Is it possible for ritu to steal the swipe from Raj and hand it over to someone else in that short span of time.
Amisha
O god I want Naina & Raj to be together.