Yes, but in this case we are not talking about a lie, we are talking about an opinion which you yourself consider a lie.

You are going around in circles. I already told it it is fair enough - if he genuinely believed Muskler was not performing a nazi salute, it just makes him deluded. I however consider it unlikely, and if it indeed is not the case, that means he was lying.

Furthermore, Muskler himself never denied him making a nazi salute, making people denying it even more likely to lie rather than simply being mistaken.