I also finished it and was disappointed.
The loss of control defence seemed to miss one vital element (an insult of grave character, paraphrasing abit)
And that the judge has to confirm that there is sufficient evidence of loss of control for the jury to even consider it.
And no real judge directions.
A trained foreperson in the jury room, who can't decide, to keep on track and correct wrong ideas would've good.
The idea that the defendants evidence was a fact and could not be disbelieved was stupid! That's the whole point of it -is he reliable and do you believe what he said!
Also murderers can well be nice people who have killed people (I mean look at midsummer murders).
A frustrating case as it should have been clearer on the timeline of the hammer part and the assistant seeing him and when an ambulance was called. But maybe that is real life cases -poorly presented at times.