Function-wise, no. But if he tested multiple times as INTJ, then there's a good chance he is a rational, introverted, and intuitive thinking type. In other words, an LII.
The whole "last letter switch" thing just means that INTJ leads with Ti instead of Ni, and that INTP leads with Ni instead of Ti. Do the MBTI tests determine which functions a person uses, or do they merely determine which type a person is based on self-reported "behaviors", "tendencies", and/or "preferences"?