FLO delays almost always keep the plane from boardg when they are of extended duration. Mechanical delays that do not impact the cabin rarely keep the plane from boarding unless they are going to take the aircraft out of service. Knowing these two facts, I would say that the unknown fix of the cargo door timmay not b the limiting factwhen th FLO delay is known to be of duration.
Once either a) the cargo door is fixed/defered, or th FLO delay is lifted/exceeed, then the final cause of the delay is known. At this point (given the 411 posted) the limitinfactor of greatest known duration is the FLO delay.
If the OP wants conspiracy theories, perhaps he should turn on the Sci Fi channel.
Edit: The plane is enroute, lss tan 1 hr delayed. Anyone know what the FLO was quoted on that aircraft at dptr time?