To be fair, I don't think Epik would go that far because to prove that Josh himself was responsible would involve them having to bring forth the events that led up to it, giving Josh more evidence for his own case. Don't think Epik believes the risk is worth the reward when they're in hot water as it is.
I think they're both in situations where moving forward would cause more harm than good so they won't do shit to each other. I think Josh hopes they'll throw their toys and do something incriminating but he also doesn't see much of a benefit in jumping on a sinking ship.
