They are managing a lot of things, they have full responsibility to be aware of these things as a company but I'd guess that with the scale of ops Facebook has regular developers never interact with the team that's managing their attempt at high availability by scattering servers across different hosts, data centers, legal jurisdictions etc. in fact I'd imagine at a op the size of Facebook that sort of problem has a dedicated department.

That said, someone should have been watching for this stuff and failed to do so (or to exist), so I'm not excusing them - but this is not a trivial thing to protect against.