Mr Banerjee's best friend was sony handycam, which captured the silence to gestures, to words, to attitude and enabled Mr. Banerjee to judge every student psychologically. It led to great success, building up a bond between the teacher and student and giving assurance that somebody in this world is genuinely interested in him.
A watchdog sybolises keeping an eye over the passers by and ensuring that nobody falls into the pit. So watchdog stands vigilant on toes. Interviewer is nothing less than a poacher and candidate once fully prepared is ready to face the bullets with a smile. Therefore, he calls himself a proud watchdog.