[and after this exchange]

[which she looks a little irritated about, tbh]

We know that one Bandit had two roles. We know that this Bandit wasn't the one manning the stocks, and it also wasn't our second Coal Miner.

So that means whoever killed Russell did have some kind of contact with the role manning the stocks. So this individual is someone who was close to Percy, and also close to the person occupying that role.