@HannaHat I kind of feel protective of SW and her brilliant writing when people miss such clear details and hence think the storyline is stupid! SW is an incredible writer and the storylines have shown just that.
As I contrast, I watched one and a half episodes of Line of Duty and found it awful (a lot of my friends recommended it but I found it hammy acting and a lot of it too obvious.) SW seems to wind complex stories, have constant tension but not make it unrealistic or hammy. With both the first two series, you can see exactly how both the accountant and the CID officer end up in the situations they find themselves in, and how things can escalate - like Faisal, neither are master criminals to start with either!