This sort of stuff is deeply worrying because it means that law enforcement are perfectly happy for the actual perpetrator to go free, so long as they tick their boxes. It would be like doctors prescribing the nearest drug to hand without bothering to find out what was wrong with the patient. A restaurant that took your order then brought you whatever was easiest to cook would go out of business in a day!
"This sort of stuff is deeply worrying because it means that law enforcement are perfectly happy for the actual perpetrator to go free, so long as they tick their boxes."
I don't think this case is good evidence of that. The problem was that they really believed he was guilty, not that they were unconcerned with whether he was guilty so long as they had someone to jail.
"It would be like doctors prescribing the nearest drug to hand without bothering to find out what was wrong with the patient."
No, it would be like doctors jumping to a conclusion too early and then prescribing based on that conclusion. That does happen fairly frequently, though, if I understand correctly.
No, they constructed the case. You and I, and everyone else commenting here, is in a database of people who read the news on an "Islamic" website. Add in a few more coincidences, hey presto, a terrorist!