Who says the car in lane 1 was going faster?
An indicated speed of 45 on the speedo would probably nearer 40 in reality.
When "Dappastyle" said they were both going at the same speed, I'm not sure if he meant exactly the same speed.
Most people including the Police accept that drivers go just slightly faster than the speed limit, 35 in a 30, 45 in a 40 , 60 in a 50 etc.
If his girlfriend was going 45 in a 40 I would say she was going with the flow of the traffic and not holding anyone up!
I think she was just taken by surprise at how fast the Supra came up.
I know which car I would rather be a passenger in!