Quite right about electrons from a circuit actually having appearance of smoke if released! - electronics engineers talk about a 'loud brown smell' - when a circuit is burning up and releasing it's electrons!
The problem with LUCAS* was use of poor quality (i.e. cheap) materials and connectors open to the elements, which corroded in a car/bike environment after only a few years - enough to get the thing out of the showroom and just beyond the guarantee period.
Look at a modern Audi or Porsche for example, and the electrical connectors are fully enclosed and sealed against water and dust ingress by rubber seals. Take one of these apart and the connectors are still clean bright and shiny after 10 years!
*Not only LUCAS. The Jaguar XJS for example should have been a wonderful car, but it was ruined by the use of cheap poor quality components.