Disapointed with how his physicists degree only amounted to a career as a lab rat in a dangerous hazardous enviroment pushing big red buttons. He had been planning for weeks to go on a office shooting spree, killing as many employees as possible then taking his own life. After the renosance casade, he had a change of heart, he decided to only kill some of his fellow coworkers and a whole bunch of aliens and military personnel.
I would guess Gordon was only the guy to push the button because he was the new guy in his group. He probably did just as much physics work as any other physicist in the place when there wasn’t a large scale experiment needing a button jockey.