The partner in full time emplyment may not be holding certificate of practice so he is not qualified to be appointed as an auditor. As the section says "226. QUALIFICATIONS AND DISQUALIFICATIONS OF AUDITORS.
(1) A person shall not be qualified for appointment as auditor of a company unless he is a chartered accountant within
the meaning of the Chartered Accountants Act, 1949 (38 of 1949) :
Provied that a firm whereof all the partners practising in India are qualified for appointment as aforesaid may be appointed by its firm name to be auditor of a company, in which case any partner so practising may act in the name of the firm."
you are thinking in right direction the firm will also get disqualified.