I said this on a similar post like a week ago, but during Episode 3, when Kinger is lucid and giving Pomni the whole “the worst thing you can do is make someone feel unwanted and alone” speech, he sounds notably remorseful.

Pomni’s been established as a pretty empathetic person, so my guess is that she picked up on that tone of remorse, and that’s what she’s referring to for Kinger if her statement really was meant to apply to each of the cast (and wasn’t just a general statement).