Unless I'm being stupid, the state of tune your car is immaterial;
You say you were doing 220kph (nearly 140mph) and this guy came out of nowhere and then played with you at 150mph+
Your car obviously isn't ill - you were able to achieve these speeds - the important point is the fact that a car with (supposedly) 170bhp could accelerate up behind you and sit with you at these speeds.
This suggests some serious power under his bonnet. I wouldn't worry about yours, I would be more interested in what he's running....