H1B is a work visa that allows U.S. employers to temporarily employ foreign workers in specialty occupations. Sarkar was likely here on a student visa, an entirely different matter from an H1B.
Later was student. But look at his history. Graduated in India and then worked at Infosys and others. This is the H1B gateway into the US. Later he became a grad student, finishing his Ph.D in 2011. He was doing some post-grad work and flipped out.