I'm slowly getting it, I am going to check out Jarrah's videos again to see if I can work out where he is wrong. I know he is but up to now I have been taking everyone else's word for it.
The real intersting part of this is Jarrah tried debating Jay and others at the IMDb. Jarrah assumes that every solar flare is accompanied by a solar proton event (SPE). SPEs have an exact definition and are generally produced by a different mechanism to solar flares. Jay tackled him on the correlation between flares and proton events (with other aspects of Jarrah's understanding).
Jarrah, after being moderated for his foul mouth, ran away and the declared he's being asked to produce proton data which did not exist in the time of Apollo. Jarrah claims that proton data is unavailable before 1976. This is complete hogwash as Jarrah uses an event from pre-Apollo which cites proton data, he's quite proud of his SPE graph which is based on proton data that he claims does not exist. Yes, proton data pre-GOES and pre-SOHO was obtained by different methods, but none the less we know when SPEs occurred. Google the Carrington event, we know space was swimming in protons back in the 1859 when that event was observed. It is considered the largest SPE in 'recent history', much larger that the Halloween storm (another massive SPE event), and occurred before modern space craft. How do we know, because of observations and core ice samples. Determining the size of an SPE does not need a spacecraft beyond the van Allen belts. The latter helps, but it is not required to know that an SPE has occurred.
Anyone can obtain the proton flux from the NOAA space weather website and find that the proton flux rarely rises to 'deadly' amounts. The flux is collected across three channels, >1 MeV, >10 MeV and >100 MeV (if I recall correctly). It's morning here and I really need to head for work, but I'll dig out more later.