Well, Gen. Richard Reboul was flying from one Military Flight Training Academy to another in a pilot training aircraft.
Salon De Provence is a military pilot training base. So no landing fees and even a possibility of legitimate business.
It's not strange that he owns a house nearby for obvious reasons, since he was the big boss of that base for years before being posted to Bordeaux.
He is also the general-in-chief of the airforce.
And a key participant in the design of the Rafale striker Jet.
Could well be internal politics, someone trying to damage his reputation (like a supplier that failed to have a bribe accepted/contract awarded). If you think that's too fanciful, one of my former bosses entered the private sector 30 years ago after exactly such an experience.