I would not blame Raman for supporting Adi or even Shagun. Shagun is Adi's mother and she's the one Adi loves most. Raman knows Shagun is not an ideal mother for his son.But if Shagun is sent to jail, Adi might not bear the trauma. So, supporting them is not wrong from Raman's perspective. We might not like it but an estranged father, who loves his son madly, will always consider his son's well- being as his first priority...However, Raman fails miserably as we see him covering up a crime, bribing police, encouraging Shagun and Adi to choose the illegal path. Here we clearly see the double standards of RKB. He could easily sort out all this mess by revealing the the truth. Shagun or Adi (whoever responsible for the accident) could have begged forgiveness and as it was not intentional, there was every chance that the Iyers would have accepted the apology. Instead, RKB chose to break laws, tell lies to all family members and hurt Ishita and Ruhi badly in the process who loved him most. Where an apology would have done the trick, Raman's twisted approach towards justice has put him in an endless abyss.