"They also seem not to have a clue about anything else, including why it was so easy to find someone to sell them high explosives."

I'm always just a little uneasy about these kinds of cases, where authorities get involved in 'setting up' the perps. Sometimes I wonder if there ever would have been a crime if they had been left to their own hare-brained devices, or if their enthusiasm would have fizzled out as the practicalities - such as how to get 'high explosives' - intervened. Similarly, some cases where a person is charged with hiring a hit-man, who turned out to be an undercover cop. Is there any reason to think the perp would have found much less hired a real hit man? On the other hand, you don't want to wait for a bridge to be blown up or someone to be murdered-for-hire .....