As this was AD Aviation's Citation ISP (titled to Frandley Aviation Partnership LLP) and it was carrying an organ it has to have been a public transport (charter) operation and so any reference to 'private' flight is misdirected. Or was it?
Of course a Cessna 501 could have been flown single pilot on a private basis - would that still be the case on a charter if there were no pax but just cargo/organs etc.?