I'm halfway through it & had pretty much the same thoughts - police incompetence etc. I reckon a bit of dramatic license makes for a more dramatic story-line - bit like some of the British press! Gripping series & well worth watching none the less. Have to say I do like to watch the French programmes - not only are they usually very good, they also help me to keep up with my French!
Also just watched The Hunt for Raoul Moat (old series that was repeated very recently) Well worth another watch - it's easy to forget just how horrific it all was for those involved & also for the residents of the area.