I have to agree with everything that Hugmonster has said there.
If passengers start to initiate their own evacuation based on a sighting of smoke, (which could be coming from anywhere), then chaos will ensue and deaths and serious injuries will result.
What had all the potential for being a safe and well managed operation by the crew, who practice for such events and know what they are doing, could easily turn into mass hysteria for no good reason at all and what may have been a minor incident could become a disaster.