how was the M.A supposed to save bani?

Ok so walia proved bani was mad so that she would be saved from going to jail for 14yrs. But how was the M.A supposed to save bani? I mean after staying 5yrs in the M.A she wld be taken back to the court right? And then she wld be sentenced to jail for 14 yrs.
So i guess walia sent her to the M.A so that he cld prove bani was innocent when she wld be taken to the court again after 5yrs in the M.A.
But walia didnt do anything in these 5yrs cuz he thought that bani was dead. Then bani came back and now he is being blackmailed my AD. Why cant he just do the thing he was planning to do when he sent bani to the M.A? or was he not planning to do anything at all when he sent her to the M.A?
Or am i just talking rubbish?

Bani could be saved after 5 yrs in MA coz the crime for what Bani is to be sentenced for lifetime imprisonment has been happened in her mental disorder state so according to law any person in this stage does any mistake/crime cannot be considered. So that's the reason JW proved Bani as mentally retard...