The '...' pretty much summarises it up.
Missions like the burning motorbike have the chance of upgrading to a garage fire - which is understandable as the bike could quite possibly be parked in a garage.
But a tractor upgrading to a harvester? Like what the... How is that possible? I am sure people know the difference between a tractor and a harvester. I just wonder how a fire can upgrade like this. Does the tractor magically turn into a harvester? Or does the fire supposedly spread to a nearby harvester? - if that is the case, then it should expand into a 'farm machinery fire'.
If I am completely missing something here, then feel free to comment below. But as it stands... This mission certainly leaves me a little confused