Jauzion had a couple of bad games for France, and was looking really off pace. Actually, he was on the bench for many Toulouse games by the end of last season. I don't really blame Lièvremont on that one, as I was also of the opinion that he wouldn't be able to regain his past form.
Poitrenaud, on the other hand, has been playing very well for Toulouse but had very bad games for France. He is a bit too creative and error-prone to be playing international level according to ML. It's true that he makes very big mistakes every once in a while.
Both cases were debated heavily and there were people for and against. So at the moment of making the selection (which, one can argue, was unnecessarilly early), they were understandable, if not unanimous, decisions. I don't anyone could have predicted the level they are playing at now (though against teams without their internationals).