You might want to re-read about that Apple-Microsoft incident.

Quicktime got stolen by an ex-Apple employee & in return Apple had Microsoft commit money & promise to have Office suite available on macOS/OS X

According to [0] it was a contractor working for both Apple and Microsoft. Not an ex-Apple employee but still an interesting read, if true.

[0] https://thisdayintechhistory.com/12/06/apple-sues-over-quick...