The way I see it..Amar does not see the point of an investigation as if Vidya did really kill him (meaning even if there is a chance for it) then it would only foil the family name as Vidya and Sagar are already dead....and that is why he avoided the investigation and told Divz to forget their previous lives...
I would be happy if Amar would have mentioned even once to Divz in front of Sin (the way he shushes Divz in front of Sin) that he cannot believe that Vidya could have killed him in his previous janam as he know how much Divz love him....Amar does not need to oppose Sin as much as he should support Divz and say he believes her when she is not talking about Sin..........But instead he just buried the matter thereby excusing himself of taking a side....
I guess I am not digusted at Amar becoz he buried the matter as opposed to supporting Sin but I do not like him either as he could have assured Divz of his affection and trust but instead he buried the matter.....😛