The case is almost always sent to a different court from the one that had its judgement overturned. The new court doesn't necessarily have to redo everything fr

The case is almost always sent to a different court from the one that had its judgement overturned. The new court doesn't necessarily have to redo everything from scratch, only the precise points that were overturned, but obviously if it was something early in the procedure then many things might need to be reviewed. I believe what contributes most to the delay though is just that the French legal system (like most others) is overloaded and it just takes time until the case gets to the front of the queue.