Do not overstate it. My expertise is in a different field of statistics. It helps I can read statistical papers - or rather read papers containing bicycling statistics. These are typically produced by well meaning doctors or cycling activists and sadly the statistics are used there to support a viewpoint rather than inform it. You can Google to find the howlers made by both sides.no one up to now has stated whether they have any specialist knowledge on the subject.
It is easier to point out flaws then actually determine what truth there may be. The fact that AFAIK there has been no definitive paper by a leading Statistician says something. IMHO the something is:
1) Any benefits/disbenefits may be small (money and reputations are about coming up with solid claims)
2) Creating a suitable model to test is extremely difficult
3) How holistic should the issue be assessed (is it just personal head injuries or the total effect on cycling and the nation's health)
There are easier ways to gain fame and fortune