So I am pretty sure that there is some truth, i.e. either he's telling the truth or he stole the claim from a teammate.
How would scum benefit from claiming this early? Wouldn't they rather keep it secret so they can use it freely?
This.
I mean I see the argument from both sides. But if we do the claim out thing they have 2 options: Truth or Lie.
1) If the Poisoner is Skum it forces them to freeze if they claim it.
2) If the Poisoner is Town, they (assumptions here) were not going to use it anyways and while it sucks to be in this spot, you really only help the team by giving up the info.
3) If the Poisoner is Skum and claims "not Poisoner", then they can continue to poison for the time being. The downside, as mentioned previously, being that they may create a slip that will later be revealed in the game.
4) If the Poisoner is Town and they do not claim it, they either have a reason that escapes me or they are being unhelpful (IMO).
If I were Skum and rolled Poisoner in this situation, I feel like the play would be to go with #3 as it grants more for the Skum team. Assuming that player is not RVSed or something on day 1 they get the ability to target night 1, and then again N2 before we even re-open the discussion about it being a thing. I think that weighed against the chances of maybe down the road there might be a claim eventually that possibly leads to them being caught makes the Skum play to be to stay silent. I mean what is the down side? The other 16 players tell the truth and then we are back at square one?
Again, just my opinion, but when we take that idea and combine it with the fact that there is like no reason ever for one of us to screw over the rest of town by lying about it... I am leaning towards truth on Iguana's claim.