Oral HSV 2 alone is really very uncommon. It is rarely shed, and it would be unlikely to pass it to someone else, but if you did, it would be by performing oral sex on them, not intercourse.
A couple of things: the person you gave oral sex to might have had the wrong test done or acquired it so recently that he didn’t have an antibody yet. An antibody test for you would have helped identify if this was a new or old infection. Did you not have that done?