According to Article 203 Section C and Clause 2 of constitution of pakistan, President have complete authority to appoint chief justice of FSC and all the judges as well.

Constitution doesnt abide president to appoint judges of FSC on recommendations of CJ of FSC instead president has the autority to appoint judges without CJ consent, so there is no need for CJ to get harsh against president. I think its just a political move to ruin the image of government in public.

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Time only knows