Overall, the situation's not fair. Violence against women shouldn't be such a menace that you would feel threatened in that situation even if it were innocent. But given that it is, and also that he was at the least being inconsiderate of your feelings, your reaction was fine.

I also second what others said about his being unlikely to just happen to walk that way right then, and it seeming likely that he was under the influence of something. How frustrating that it was so close to home, and lucky that you live with another adult.