I think you got that wrong, he didn't say they were coworkers. But sure, that'd be very different.

No it wouldn't.

A coworker stared at my boobs for a little too long and I felt immediately uncomfortable and put a jacket on. If he ever expressed interest in a romantic relationship, I would feel really uncomfortable, and probably quit.

Not really, direct communication, eye contact etc... If one cannot do that, facebook friend them and try to tell them that way. The worst they say is they are not interested.

It's a numbers game.

Uh, meanwhile in the professional world, this kind of behavior gets you fired. I heard Netflix has a five-seconds rule of eye contact, for crying out loud.