Perhaps he wasn't actually racing and was just casually trying to overtake. Until you felt the need to prevent him doing so?

If I was him, I would have just done the same.
It's funny the number of car forums I've been on where people claim they ran circles round some Skyline, Porsche, Subaru, or [insert performance car here] .....did it actually occur to them, the guy they "wasted" might not have actually been trying to race at all !!?
Bit like being at the lights then someone pulls up alongside - rather than speed off on Green, you wait a few seconds, AFTER they have sped off on their own - makes them look like a tit, in a race on their own! LOL.