Knowing the writers I doubt they would show him doubting the great Mataji. However, he does owe it to Vidya, so he might listen to her more and not stop her from doing her bondgiri. He wont be Di's chamcha anymore but I dont think he will doubt her right away either... unless ofcourse they prove us all wrong and give us a new track where Sagar does remember Sindoora pulling the ventilator off and smiling while he was dying..