Thanks, Tricky. I had zero memory of anything previous to do with the Duckface/Footman shenanigans.
The lack of character development maddens me at times, or that a character is allowed to develop for a while, then snaps back into their previous one-dimensional incarnation, as if the writers had completely forgotten the intervening changes.
It happens a lot in DA. Thomas is a classic example. He has story lines (the highly unlikely 'coming out in a 1920s country house and everyone being fine with it' among others) that allow him to appear briefly complicated and three-dimensional , but then snaps back into being a motiveless Iago-style villain purely out to create chaos upstairs and down, stroking his villain-beard and cackling to himself.
(And surely, whatever his precise relation to Baxter, Cora's point is a perfectly obvious one that should have occurred to any self-respecting villain - even if he's interested enough in getting extorted information about his fellow-servants and employers to import a lady's maid he has a hold over, isn't he in fact putting himself at significant risk in that him disclosing her criminal past exposes him as having knowingly placed a convicted felon in Cora's bedroom?)
And what's going on with Molesworth? 98% of the time he's presented as an idiot, hapless laughing-stock, but in any scene with Baxter, he's suddenly a subtle, insightful, morally courageous combination of agony aunt and romantic hero...