It is true that Raglak can EASILY mistrust swasan.
I agree that the Situation of Raglak is really worse. And for ragini everything in the world is after LAKSH. Laksh is so important for her. When she saw laksh in that condition she shut all her senses and blindly believed that swasan especially sanskar is responsible for the state of Laksh.
So just like that when the inspector shows her a video she believed it. I have no doubts that if the inspector said that AP is responsible for LAKSH's state she would have believed that too. Because Ragini will believe what she wants to believe. She will just react in the present without thinking about the character or past deeds of the person whom she is accusing even though deep down in her heart she knows that they are trust worthy.
Laksh, by the looks of him and also by silence I think he also mistrusts sanskar. Since he didn't say anything (may be too weak to protest Ragini or not able to speak because inspector might have broke his mouth, whatever giving him benefit of doubt)I can't able to conclude whether he believes sanskar or not.
To conclude they believe people based on their situation...