Its hard to tell just how serious these accusations are. For instance
>the airman who served as second-in-command only had a student pilot certificate
Presumably the first in command did have a full certificate (otherwise why wouldn't they mention it). The reality of this could be as mundane as "the guy sitting shotgun in the Cessna is only half way to his PPL and we bought a friend along".
Legally Tapjet may squeak by if their counterarguments are legitimate. At the very least fully rescinding their license may be overkill. This decision might be politically targeted at anyone trying to be Uber of the skies. I'd want to see more than this one off press release before calling them reckless.