If someone wants to hire somebody and they agree on a salary, that's fine, however it wants to work.
When that employer presents the salary it will pay to the woman, they're not also presenting the salary they would pay to a man so that she can compare and decide it's ok to take less money. His premise is based on the woman already knowing what the salary range is for that job. She doesn't. In fact, when it comes to salary, most companies have rigid and strict rules against talking about how much each employee makes.
A female employee at my job had that experience and it was only because a manager inadvertently sent her some paperwork to use to fill out what she needed to fill out. That was when she saw that she was being low-balled $5/hr. The guy's name who was on the paperwork was way, way, WAAAAY less qualified than she was; had been in the business for a lot less than she had been and did not turn out to be a good employee (he was subsequently fired for falling asleep on the job). Needless to say, when she found out, she burned the place down. It came down to the fact that the HR person lied to her about what the job paid. That manager's boss almost fired the manager over that because it violated the LLFPA not to mention the blatant sex discrimination that was laid bare.
If companies can't be brought to opening up a can of Act Right on their own, then yes, the government needs to stick its nose into the process. I can't see how any of those people in that audience can be ok with their daughters and granddaughters or nieces being short changed because they're "cloven and not crested", to quote Queen Elizabeth I.