I agree that Napoleon was surprisingly lenient with those who betrayed him even before 1814. For example, Murat, Caroline Bonaparte, Talleyrand and Fouche conspired to alter the succession while the Emperor was missing in Spain and believed dead. This was clearly treasonous behaviour but Napoleon merely sacked Talleyrand and delivered stern reprimands to the others. A similar conspiracy in other European states at that time would probably have resulted in the imprisonment or execution for all concerned.

Far from discouraging such behaviour, his leniency emboldened the conspirators with the disloyalty of Talleyrand and Fouche being well known. Murat actually joined the Allies in a futile attempt to keep the throne of Naples in 1814 but had the nerve to return and ask for a post during the Hundred Days. Despite this treachery from his former friend, the Emperor merely refused to see him when many rulers would have had him shot without fear of political repercussions. As I'm sure you know, Naples later saved him the trouble, which was a sad end for a brave soldier but hardly unexpected considering his actions.

While Napoleon is often castigated for ruthless acts like the execution of the Duc d'Enghien, people often forget that he could be forgiving to a fault regarding his family, ministers, generals and others who had let him down.