Does Mr Dunne really believe in what he says? I would have thought that any risk associated with aviation would be based on flying hours, or flights, and not man-years, as presented in RA 1210.
I would expect the risk to be understood in terms of flying hours, or whatever other scaling factor is relevant to the industry or field concerned, e.g. controlled flying hours for ATM. In the case of the MAA/MoD it then also chooses to 'normalise' this to risk to the individual per annum. All quite normal and allows comparison and measurement against HSE guidance and the MoD's legal obligations.
S-D