It's clear he didn't stab Sarkozy in the back - since there were no defaults on the UMP side for Sarko. (Let's not forget Chirac's long experience in candidate-killing). This to me means the deal between him and Sarko is real (it has scarcely been denied, btw), so expect at least the ten-year limitations statute or some other jiggery-pokery to keep Chirac out of trouble with the law.