+1 Pedestrians account for more fatalities (fourfold) than cyclists, so where are their helmets and arm/knee pads?
While TT helmets are primarily for aerodynamic benefit, many of the older ones used in Britain under CTT regulations are actually just aerodynamic fairings offering no protection whatsoever. More modern offerings which must be used by the pros do meet EN1078 safety standards. Bald time triallists may actually derive more benefit from not wearing a helmet.
TT was probably the one near Newport (U7B) - nice road that.
EN1078 helmets are banned for racing in the US as they are not deemed to offer adequate protection!