Ignore the threat, get him medical help, and then shore up a defense for yourself by providing an accurate description of the accident to the police. Also, you should have a camera with you, take photos of the accident (where your car is, where his bike is, where he landed) so you can reconstruct the whole thing if you need to. You don't need to tell him anything at all. If he hit you on the right side, and you were in the right lane, then you don't have much to worry about. If you were turning across a lane and you cut in front of him, then it'll be a toss up but likely his fault if he was truely way over the limit (in the US, that would equate to >15MPH more than the speed limit, but obviously there are other factors) Also, a gas station should have video footage and probably caught the whole thing on tape. I honestly wouldn't have paid the guy anything. Also, in the US if over $500 of damage was done the police must be involved.

(note, I screwed some stuff up because I am from the US and didn't realize you were from the UK, but you should still get the point )

@squirrel - Yes, I've seen a lot of riders do way over the speed limit (i've broken 120 mph myself) but that doesn't change the fact that there are a lot of really good riders out there, sports bikes included. I've riden with a rather large group of enthusiasts who all ride sports bikes, and every single one of them will refuse to ride if anyone doesn't have at minimum a helmet, gloves, jacket, long jeans minimum, and boot. At the company I work for there is only 1 irrisponsible rider out of the 20+ that pull in every day. It is sort of like the black guy that gets accused of being a criminal just because he is black.

Wearing personal safety gear doesn't make people responsible drivers ...

Anyways, I don't doubt that there are safe riders out there; but I think that when a large portion (from my experience the vast majority) of well known motorcycle accidents between cars and bikes involves a motorcycle rider who is driving recklessly on an unbelieveable level there is going to be the assumption that the rider was at fault unless there is something to indicate otherwise.

I'll throw this out there for non-motorcyclists. (based on US crash statistics which I have on paper, but no link to)

~25% of motorcycle accidents are single vehicle accidents where the rider went off the road or hit some stationary object. About 2/3rds of these are due to excessive speed for the riding skill.

~75% are multi vehicle accidents and typically between 1 motorcycle and 1 automobile.

In the multiple vehicle accidents, the driver of the other vehicle violated the motorcycle right-of-way and caused the accident in two-thirds of those accidents. So the automobile was at fault. The most frequent accident configuration is the motorcycle proceeding straight then the automobile makes a left turn in front of the oncoming motorcycle. I'll also throw in that people 20-29 and older than 65 are the biggest offenders. So, to recap, it is typically the automobile drivers fault.

Motorcycles equipped with fairings and windshields (sports bikes, touring bikes, and standard bikes, the sports bikes probably don't contribute to the underrepresented though) are under represented in accidents, most likely because of the contribution to conspicuity and the association with more experienced and trained riders. Motorcycle modifications such as those associated with the semi-chopper or cafe racer are definitely over represented in accidents.

bugrimmar was he a thug since he made you pay for the x-ray?

Well, I could have just said they were defensive drivers, but I was trying to show somehow that they are. People who wear protective gear are typically better riders and more defensive drivers. Obviously not always, but most the time.

Also, just because you see a motorcycle speeding does not mean they are irresponsible drivers. It is well known that motorcyclists getting rear ended is the second biggest multi-vehichle accident, so a lot of cyclists try to make sure they don't get overtaken by travling 5-10 faster than surrounding trafic.

he didn't make me pay. i paid him voluntarily coz i cared about his injury, despite him being an idiot.

Oh, it's understandable.

I deliberately stated well known motorcycle accidents involving cars and motorcycles because we were dealing with the preception and not the reality of what caused the accidents ... and in most major centers accidents become well known because someone did something reckless, dangerous and/or illegal which lead to someone's death or serious injury. When 90% of the accidents involving motorcycles you hear about involve a rider doing something remarkably stupid the initial assumption of someone when they hear about an accident is that it was the riders fault.

LOL

im an idiot. 

Yeah, you shouldn't have paid at all.

Do you just hand him money or did he actually pay for an x-ray? Not only that but if he does take legal action the Judge may see that as a sign of guilt.