The reticence to refer to evidence in the bicycle helmet debate is analogous to the cot death debate at the end of the 20th century.
It was recommended that babies should sleep on their fronts from the mid 1950s and this advice continued without reference to evidence, up until 1988, despite the knowledge that had been around for many decades that this very advice was ‘likely to be harmful’. A more rigorous review of preventable risk factors for Sudden Infant Death Syndrome (SIDS) would have led to earlier recognition of the harms of sleeping on the front (see Dr Ruth Gilbert – “How wrong was baby sleeping advice"
If we can get that so wrong why don't we have the humility to recognise that we can get the helmet debate wrong too? Helmet research has left many questions unanswered, and the lack of scientific rigour that is the current modus operandi for our governments is deplorable.