Olivia Colman was just as good as Mme. T as I thought she'd be. There can never be enough Colman. I did gasp when Thenardier slapped her, though. I'm sure I've never seen Colman slapped before (although I wanted to slap her character in Fleabag all the way across the Thames and back, she was that horrible).
I had to laugh that Mme. T had a Cockney accent. I know it's meant to be signifier of a lower class, but it just added to the mishmash of French/English accents. I hear a little needle scratch every time someone says, "Yes, monsieur" in the middle of an otherwise English conversation. It would be like me saying, "Ja, mein herr" here in California.
Agreed with those upthread who think this Javert is underwritten and underplayed. And for a town with low crime levels, there sure seemed to be enough obvious prostitutes he could have arrested for soliciting, not to mention their johns.