When your a wealthy citizen who the IRS understands and your integrated with the US political machine, yes, it's just tax paperwork. When your the kind of person with a lot of abnormal imbalances with cash vs. how they understand you, an outsider to the political machine, your audit score goes up and you get a lot more scrutiny in general, because your a high value target to collect more in taxes and such. You get more unpleasant interactions at any government interaction checkpoint. It's bureaucratic, but still unpleasant and could land you jail and to them, it's just another day at the job where the computer machine said to poke you more.

The person we are talking about here is immigrants with dirty cash basically, not doing it properly, a pretty different kind of person in the US gov's eye, and might be drug related, which is a great career boosting lead for their buddies at the DEA.