You are assuming that Apple has great cross-team communication. By many reports, they do not: I've heard that one team does not know what another team is working on, much less the status of that project.
I remember reading a couple of articles about Bell Labs and how they had a huge cafeteria everyone was encouraged to eat in, thereby promoting cross-communication and "cross-pollination" of ideas and insight. I kinda wonder what the Big Tech companies would be producing now and at what rate if they did that instead of letting or encouraging everyone to sit at their desks all day long (mind you, Google seems to be pretty good about that part.)
Worse than a simple information "spy" would be having a security engineer with intimate knowledge of Apple's security leave the company to co-found a new company whose entire business model is to sell expensive hardware to law enforcement that bypasses Apple's security. Oh right, that actually happened[1].
An Apple security engineer discovered–or baked in–critical security flaws at one of the world's largest technology companies and instead of disclosing them to the company, co-opted that sensitive insider information to start his own lucrative business. I've been waiting for news of this man's reputation, career, finances, and perhaps even his freedom having been taken away; so far it seems he's gotten away with it. I don't buy the apologist explanation I've heard: "he's likely just so good at his profession that he reverse engineered entirely new vulnerabilities after leaving Apple, without necessarily having exfiltrated knowledge only obtainable from within Apple's own walls".
If this man had done this to a bank or the government, he'd be rotting in federal prison. But he "only" expropriated this information from a private corporation, so no big deal. /s
[1] https://www.forbes.com/sites/thomasbrewster/2018/07/26/apple...
Remember also that the entire concept of intellectual property is a legal fiction created to prop up revenue streams, as well.
Okay? But that's not what that company does at all.