You could argue that Facebook should be more explicit in asking developers to self-certify and label their data correctly, or not send it at all. You could argue that Facebook should bolster their signal detection when it receives data from a new apps for the first time. But to argue that a human at Facebook blindly built a system to ingest data illegally without any attempt to prevent it is a flawed argument, as there are many controls, many disclosures, and (I'm sure) many internal teams and systems designed exactly for the purpose of determining whether the data they receive is has the appropriate consents (which it did, that Flo sent to them). This case is very squarely #1 in your example and maybe a bit of #2.