In my limited experience, it's very rare in a rear end car on car collision for the rear ender to not be found entirely culpable. Obviously culpability should be heavily considered when the accident is fatal, as is likely in the case of a rear ended cyclist, however the idea that as a cyclist you're life hangs in the balance every time a rear driver doesn't pay attention is frightening, especially when a legal precedent such as this is set, which seemingly just puts such events down to an unfortunate accident.
+1