Earlier quoted context omitted.
Mo Farah didn't cheat the system though. He was a victim of the trafficking and so the ops point is referring to not criminalizing the victim i think. Which makes sense. He didn't break the immigration law.
He is a direct beneficiary though. Whether that is relevant in immigration law, I don't know, but it certainly is in other areas of criminal law (e.g. receiving stolen property, soliciting murder etcetera).
Being in possession of stolen property is not necessarily a crime. If you buy something on eBay that was stolen without your knowledge you're not going to get charged. You may have to return it and be out of pocket probably, but not crime.
As for soliciting murder that's a crime. There is an intent there.
> He is a direct beneficiary though.
What if instead of his lief today he was forced into the sex slave ? Would you still consider him a beneficiary ?