The mystery here is why would BBC take a masterpiece and adapt it into this? If you are a Christie fan watch it to keep your streak going, but seriously, it's the worst kind of adaptation that I have seen of Christie's work, of course tied with the Amazon one. Very subpar.
Clumsy accusations thrown around, cartoon characterizations (almost no background so you can't feel empathy towards anyone), and very poor writing and direction it would seem.
And last, please stop trying to give us some kind of social messages this way, there has always been critiques of society in almost every artform, but not with dialogue taken from the justification of a judge's sentence or from politicians' speeches, this are supposed to be normal people in extraordinary circumstances.