"Did a man with excessive demerits get fired?"
Accumulation of a specified number of demerits was cause for dismissal. An example would be an accumulation of 90 demerits. However, if an employee maintained a clear record for a specified period those demerits could be cleared from their record.
Demerits were assessed in multiples of 10, starting with 10 and going to 60 for any one offense. The amount assessed depended on the seriousness of the offense. Being responsible for having a motor car struck by a train was pretty serious. Again, circumstances would be taken into consideration as to the penalty assessed for each case.
Jimmy