Ruddy heck lecky.... would not have thought it was so controversial, and I am not sure adding another 20 pages of evidence is helpful to the thread!
Will have to dig up some old stats I have read.
Just picking up a couple at random...
Following is plausibility not proof...
http://www.cyclehelmets.org/papers/c2014.pdf
Holds that the risk to a cyclist is around 1 per 5.6 million hours.
Following is guestimate: Fell running we have around 500 races a year, with average 100-200 participants, on average running an hour in each one (more shorts than longs) so order 100,000 race hours a year across all participants. Fatalities around 1 every 5 years ie 1 per 500,000 hours. (probably more risky because there are more running hours now, than in the past, so past fatalities were occuring on fewer running hours)
So roughly an order of magnitude in it.
None of this exact but roughly illustrates the point.
As someone point out, the number of incidents is so small that the numbers do not hold much statistical significance as a measurement, rather than detection of risk.
Stats tell there are 30 times the number of serious accidents than fatalities road biking (presumably means life threatening...some govt agency figure) . I am guessing that there are far fewer serious accidents fell running as a ratio of fatalities, So serious fell and road cycling accidents are not dissimilar per hour - same order of mag. Point I am making is fell running is still not more massively risky than riding (or driving) to the lakes! Less than/only an order of magnitude in it.
The other point I was making, that the health benefit of running and fell running undoubtedly is far greater in reducing mortality, than the small incident rate increases it.