As Henderson was an experienced pilot, he would know (although unlikely to admit willingly) that an AOC operator was the only lawful way to fly Sala to & from France.
The TIMES had reported ( alleged ) that Henderson had done a number of flights for Cardiff football club. Their regular pilot? That also raises some interesting questions as to these arrangements. Did Cardiff have their own aircraft and Henderson was the company pilot? Was he qualified even for that?
No doubt when the Inquest is held all will be revealed, unless of course the CPS decide to charge anyone in which case the Inquest will be delayed until the criminal process is completed.
Off topic: the law changed following Lord Lucan 'disappearance' in 1974 when the Inquest for the nanny announced his guilt without a criminal trial first.