He certainly is a fine debater - and more worthy of respect than most other right-wing pundits.
If that's supposed to be the end of the discussion - I don't know how your video continued and if this woman elaborated further afterwards - I assume Shapiro's idea is what I mentioned in my subject line. But I would doubt that that's what she actually meant.
If we're talking about possible borders, there's the 1947 UN partition plan, and of course the de facto border after 1949 - which would be the same as the 'pre-1967' border. And which is also the internationally recognized border of Israel, the line separating Israel itself from the West Bank and Gaza. I'm not sure what pre-1973 is supposed to refer to.
Though by now, Israel has expanded so much in the West Bank, particularly with the Jerusalem suburbs, that a modified version of that border seems more workable than the strict definition - there are a good number of settlements that would have to go, no question about it, but areas like Maaleh Adumim are a lot more difficult.