It's wrong to blame someone for something without having proof.
Greg has lost his wallet and is looking around for it when he sees Neil is nearby.
Greg wants to ask Neil about the wallet.
Greg asks Neil if he might have seen a wallet that he thinks he dropped around the area.
Greg asks Neil if he took his wallet and to give it back to him right now.
Neil tells Greg that he hasn't seen it but that he'll help him look for it.
Neil is angry and scoffs at the accusation and tells Greg that he had nothing to do with it.