Although I am glad they concentrated on Dawn Sturgiss and her family in the last episode, I think that having virtually no info about how the authorities went about dealing with this second incident sploit the story telling.
And still do not understand why the portrayed as this sort of run down defeated person and all who talked about her and the final real life video showed her to be quite a different sort of person. Most of the other people they had tried for some similarity.
I was also a bit confused about the bins still being full after what might have been quite a few days and it being found by Charlie. He was apparenlty known for skip diving which is why we had the earlier scene of him retrieving a stool and something else. (Couldn't quite workout how he seem to have been able to rent what seemed like quite a big house!)
I wonder is they glossed over how the poison actuallyl ended up on the door handle because now they are not so sure. At the time, or shortly aftwards, it was written as though there were 2 sealed bottles (ie very dangerous to carry something so lethal that wasn't) to have a back up source. The one used to spray the door handle could be anywhere, I can imagine that having been opened they took it back on the train with them. The other was just dumped because they didn't need it.
Have just checked the dates and the Skripals were poisoned on 4 March and Dawn and on 30 June. So even allowing for lockdown this doesn't make sense about the bins not being emptied. But maybe as someone said up thread he found shortly after the poisoning and only gave it to her later.
Or ... plot for a second drama ... there was a second Russian hit squad who came later to target ???
Its good that the people involved felt able to be seen to be part of it.
And yes the husband and son of Tracey must be totally embarrassed by how they were shown in the drama.