Watching Beret intending to vent his pent-up anger, Lynch knew he was safe, still very safe.
A scholar once said—
"If you display intelligence beyond that of ordinary people, even your enemy will covet your wisdom and desire to take it for themselves!"
Simply put, a not-so-smart person has an inherent trust in smart people, and this trust can sometimes cross camps and positions, it's quite amazing.
He used the simplest way to make Beret understand he was doing pointless work, so Lynch was safe; in Beret's eyes, Lynch was already one of them.
Even if not, a certain friendship was established, so when he left, he used "kill them" instead of "kill you," distinguishing Lynch from those people.
Actually, Lynch said what he could understand, and there are many things Beret couldn't understand, like signing encryption.
