It was more tongue-in-cheek and a bit over the top with “every” deal, although how many deals last year were funded 100% by Austin capital? Not that deals need to be 100% Austin capital, but your mentioning dozens of companies were funded by Austin investors may be a bit misleading too in that they may have taken some money from others outside of Austin.
I have had stories related to me recently (and through personal experience) that investors in Austin ask you to get a lead before they will join the round and that leads the companies to head east or west because of the limited number of firms that can lead a sizable round here.