Coming out of lurking to say on the whole it was fantastic, the acting was amazing, for the most part so was the script. I loved the ending being a tense two header rather than a violent dramatic showdown, but that we did get a bit of that in the car, and that TLR wasn't two dimensional.
However, I agree I wanted to see more of the Joanna / Faisal / rob storyline in the last episode. Not because I need spoon feeding, I totally understand was happening with it, but because that storyline was shown in great detail in earlier episodes, the viewers got very invested in it, so I think it deserved more than a few sentences of exposition thrown in at the end. And as much as I enjoyed Catherine giving CID all the info to tie it together at the end, where were we supposed to think she'd had time to research the pharmacist in amongst everything else that had happened to her that day? And was she actually going to tell anyone if the detective hasn't happened to pop in? It was all a bit too convenient. It's a pet hate of mine when writers seem to run out if time and rush endings, and I had hoped it wouldn't happen with HV, because the writing is generally so good, but in the case of that one storyline, that's how I felt.
I get what people are saying about policing going on after Catherine left, but we hadn't only been seeing that storyline from Catherines point of view, we had been watching it from the others characters points of view and it had been given huge importance early on in the series, so it seemed off not to give it more prominence at the end.
I think a 90 minute episode would have done the trick (an extra 10 mins seems odd too, like they couldn't possibly edit it down to fit the original time, but didn't really want it to have a proper longer slot).