How do you know they didnt install a rootkit?

If you have a modern iPhone and don’t want the crazy hacks, a very very simple but effective tip is to power off your iPhone when exiting the aircraft. When the device powers up it is in “before first unlock” mode and is severely restricted in what it can do. The attack surface area is significantly reduced. They’re not going to burn one of their $100,000 per install exploits on your BFU phone the same way they do with a full physical access unlocked paid exploit.

Also lockdown mode to reduce attack surface area.