Why was the undercover officer trying to kill Hook at the end of the movie? They had spent the whole film trying to recover him - why then try to kill him? -------------------------------- My God, it's full of stars!
Because he saw one of them at the loyalist bar helping to make the bomb that exploded. It mentioned the Ormeau Road as a target for the bomb...maybe the bomb was to be planted by the loyalists and blamed on the IRA. I know that has happened during the troubles in an attempt to turn the Nationalist population against the IRA. I'm not sure if thats what was happening in this scenario, but either way, the undercover agents where obviously corrupted as they were working with the loyalists.
Yes the bomb exploded by accident, we know that because the MRF (undercover British) guys who provided the bomb to the Protestant terrorists were driving away from the pub when they were surprised that it went off, and discussed how clumsy the Protestant terrorists (the people with the bomb, who caused the explosion) were.
As to the OP's question, the MRF tried to kill the British soldier to cover up the fact that they had illegally supplied a bomb to Protestant terrorists, which he had accidentally witnessed. I find the MRF's decision to kill the British soldier implausible, as discussed on my thread here titled "Implausibilities".