The cyclist, if.

If they stick around.  That's a problem for sure.  Not as big as trying to prevent them from leaving (which is basically unlawful detention unless you're a cop), but a problem nevertheless.  In the event of a collision with a car, the cyclist is likely to be injured and not moving all that much, so this isn't that much of an issue.

If there's any real damage.  Most bikes are 85kg of mostly flesh travelling under 15kph, which results in virtually no force and therefore virtually no damage (notwithstanding the complete stoner that i watched run into the back of a praked car on Sunday night).  

And if they're at fault.  I've had two collisions with pedestrians, one of which left me with a major concussion, and i made sure that each of those peds was charged, since there is NO situation where a pedestrian can be on the road lawfully.  I'm suing one, and i WILL win.  The vast majority of collisions between car/trucks and bikes - the cyclist is the victim.