The money mule themselves is almost certainly insolvent to pay the damages. Currencies can also change by the money mule (either to a different fiat currency or crypto), putting the ultimate link completely out of reach of the originating country.
If intermediary banks are deputized and become liable in a no-fault sense, then legitimate transfers out become very difficult. How does a bank prove a negative for where the funds come from? De-banking has already been a problem for a process-based AML regime.