You have mainly lawmakers passing judgement on other lawmakers, and the "judges" may owe favors or "future considerations" to those in power. The fact that in none of the 5 cases there has been even a nominal  prison sentence suggests that these trials are just for show - to create the illusion that something is done.

"The case was only the fifth ever heard by a special French court created in 1993 to try ministers. The court, which is made up of 15 judges, including 12 lawmakers, has never handed down a firm prison sentence."