Ah, OK now I think I'm with you: in that instance, I agree, it probably isn't dangerous for those two flights in isolation. But perhaps if we remove the IR element, both might be considered foolhardy?
If you make the comparison specific to this flight, then yes, you are right! Paradoxically, if Mr Ibbotson had been a “plain vanilla” PPL with no instrument training at all, he might (should!) have declined the flight as obviously being beyond him.
But that said: see also the JFK junior accident:
https://en.wikipedia.org/wiki/New_Jersey
JFK junior wasn’t being paid, but died (and killed his passengers) in an accident not completely dissimilar to this one (no CO poisoning but VFR Pilot, and SEP over water)