But it's Apple, which is a huge target. Never mind these individuals, you will have China, Russia and other seeking to infiltrate it.
In any top r&d area, one wonders if they perhaps should be searching staff on way out and making then sign out and return CAD drawings etc.
You get trustworthy people by trusting people. Generally when I was there there was a presumption of trust. Given how blatantly the defendants are alleged to have acted, that’s still the case.