So i think its obvious now that Hawkins was either of the following:
1. One of the terrorists or group that did the bombings
2. Is a traiter from the group or terrorists that did the bombing.
3. is a spy that infultrated the group or terrorists that did the bombing.
4. is just a well prepared ex spy.
I think he is most likely either the traiter from the group or infultrated the group. He implied that he had a bomb in his steel drum and thats what they attempted to use in nyc.
And the guy that came back is obviously lying and not telling them everything he knows.