Conducting a monetary transaction intended to conceal the proceeds of a crime is the very definition of Accessory after the fact. His question was about a monetary transaction where he's been told that it's the result of a crime.
As a general rule you are not required in some states to report crimes you are aware of (though in some you are, know your states law!). But if you assist the perpetrators in the crime, such as through concealment or laundering of funds you are an accessory after the fact. Your link doesn't explain very well that accessory after the fact doesn't just apply to concealing the crime (it implies this) as laundering the funds or assisting in disposal of assets where you know of the crime makes you an accessory. You can be an accessory by doing anything that assists the criminals in their crime.