[PeterisP]

For large amounts such as this one IMHO the key issue is that the recipient can be questioned about the source of the BTC - are they themselves related to the actual crime in question? And searched for evidence of the same.

If they're innocent, they will generally be able to identify the counterparty to whom they sold the goods or services valued at close to $1M, and the goods&services may then lead to the culprit; because (here's the thing) if they "just" did a fully anonymous $1M cash or cash-equivalent transaction, then they're not really innocent in many jurisdictions, because for large amounts money laundering laws generally (nuances depend on country) require you to identify the other party or not do it. Selling something anonymously for $10 in cash is innocent, but selling something intentionally anonymously for $1M in cash (or BTC) generally is a crime of money laundering by itself, no matter where the money came from.

The original article assumes (with no grounding, but just as an example) that the 'innocent recipient' might be some over-the-counter broker. That broker is legally required to 'know your customer'. And if they don't know their customers, well, then they're not innocent and deserve to lose their money.

The same applies to Bitfinex itself - they're required to know from whom they got these 96 BTC. If they don't, well, it's their problem, why not fine them the equivalent of 96 BTC or more for that.