If a conveyer breaks and bags have to be off loaded by hand IMO opinion that is in the airlines control since preventive maintenace would prevent it.
Um don't mean butt in...but if a conveyor breaks...that's NOT within the airline's control. Airline's don't own nor maintain airport baggage conveyor systems. That's the airport's job, and the airline's pay a fee to use the systems.
What and whose definition of severe weather will be used?
There are also times when say a lightning storm hits an airport, the control tower will order all ground activity to cease. If an airplane parks at the gate and passengers are being offloaded, this could potentially be in the middle of offloading cargo and baggage from an airplane. If an order to stop ground servicing because of safety is given, ground crews have to stop what they are doing. So while you may get off our plane and to baggage claim, your bag may not because ground crews couldn't finish their job in the 25 minute time window.
Those exceptions were put in there for a reason. Not just to make it so "vague" as to make excuses for anytime it takes over 25 minutes.