Years ago on a Continental flight from LHR to LAX we made an emergency landing due to (loads of) smoke in the cabin, I was quite young at the time so don't fully remember the situation or where we diverted to. The point is it was caused by oil leaking into the bleed air, a very similar situation.
Very strange on how the FAA found no evedence of smoke, maybe one passenger got a bit upset about something (similar to when you can smell fuel before taxying on some jets) and the panic spread through the cabin?
Our crew handled the situation much better; the oxy masks did drop but we were told by the CC to NOT use them and instead breathe through damp passenger blankets. Also, we did not evacuate using the emergency slides we just walked off the aircraft using steps at the airport. No injuries.
Seems there was some kind of breakdown in CRM...