The day Sanchi-Shravan are leaving the hotel, pappu comes up to sanchi and gives her the rest of the two formulas, right? well, when sanchi heads towards the car after that, pappu says something like this "Sanchi di, kashmera and me are the only ones who know the truth and we'll keep it to ourselves till the right time"
im pretty sure what he means by that is nothing happened that night. kash and pappu most probably came into their room and took the photo, sent it to nidhi and all that. because if you remember, the photo was obviously taken at such an angle which would've been impossible to get by shravan keeping in mind he was busy staring at sanchi.
well this is what i think.
what do you guys think?
note: sorry if someone already said this earlier. 😛