I agree it came out confusing on the show... but reading the details on Fred's site, it's a two-tier progressive income tax -- the family in the scenario is taxed 10% on the first $100k (after standard deductions/exemptions), and then 25% on everything over that. It's not 25% on everything if they make over the threshold, it's just 25% on everything over the threshold.
Should have included you in posts 38 and 40