I don't know how this guy drove the Fiesta, but if you look at reported mileage from owners, the Fiesta does get excellent fuel economy. The average reported mileage on fueleconomy.org for the manual is 36,5 MPG (US), so 6,4 l/100 Km. For the automatic version, it's 33,5 MPG (US), so around 7,0 l/100 Km.
The transmissions are geared pretty high though, which makes the Fiesta much slower than its power rating would indicate, but this does result in great fuel economy figures in real life driving according to the owners themselves. Well, unless the driver is a moron who keeps the engine at 3000-4000 RPM at all times.