premise: An explosion, followed by a raging fire, demolished a plastics factory, killing at least three people and injuring at least 37.
hypothesis: plastics are sturdy things 
reason: Plastics might be sturdy and durable, but they have little to do with the target sentence placing this in the neither definitely correct nor definitely incorrect category. I'm not quite sure why the model didn't catch that particular statement. It must have struggled with this particular word pattern.