I smell a rat with these growing suggestions that the cause is some type of industrial action by baggage handlers. See in 14 below from the EU Regulations.

FROM EC 261/2004

(14) As under the Montreal Convention, obligations on operating air carriers should be limited
or excluded in cases where an event has been caused by extraordinary circumstances which
could not have been avoided even if all reasonable measures had been taken. Such
circumstances may, in particular, occur in cases of political instability, meteorological
conditions incompatible with the operation of the flight concerned, security risks, unexpected
flight safety shortcomings and strikes that affect the operation of an operating air carrier.
(15) Extraordinary circumstances should be deemed to exist where the impact of an air traffic
management decision in relation to a particular aircraft on a particular day gives rise to a long
delay, an overnight delay, or the cancellation of one or more flights by that aircraft, even
though all reasonable measures had been taken by the air carrier concerned to avoid the
delays or cancellations.