It would be the same as an outside source accessing a gaming joystick which is hardwired to the game controller.
Wireless fly by wire is still in the development phase and not incorporated on this jet.
So as I understand it an outside source could not “take over” the jet.
However, I have been wrong before too.
I’m not aware that any fly-by-wireless system has yet been approved. Personally, I have some concerns about security. So far, the certification authorities agree.