The guy missed a third option for powering Mars vehicles: compressed "air" engines. On Mars the "air" is CO2, but the actual gas is not that important. On Earth

The guy missed a third option for powering Mars vehicles: compressed "air" engines. On Mars the "air" is CO2, but the actual gas is not that important. On Earth compressed air vehicles were tried, and they mostly failed, but that's because there are other more efficient alternatives, like the plain old gasoline powered cars. But on Mars, the simplicity of spinning a turbine with CO2 coming from a pressurized tank is hard to beat. You would then let the CO2 vent in the atmosphere.