The article describes the top speed of the helicopter keeping pace with the car as being well below the stated record, ergo the pilot knows the car wasn't going

The article describes the top speed of the helicopter keeping pace with the car as being well below the stated record, ergo the pilot knows the car wasn't going that fast. It also states that analysis of the engine and gearbox ratios indicate the car is literally incapable of going that fast, therefore the engineers who built it know that as well.