Ruiz's interrogation of Serra was nothing special, primarily focusing on his involvement in organized crime activities, such as gang-related operations and drug trafficking. Mahong's use of terrorism as a pretext didn't quite fit in this context.
Mahong could make use of it because Jimmy was indeed investigating an explosion. After linking it to the explosion in Newark, Azte's attack on Jimmy could neatly fit into this narrative, thus avoiding the FBI's deeper probing into the case. The mastermind had someone attack the investigating agent, ensuring there would be plenty of suspects.
Involvement in such bomb terror attacks was something ordinary gangs could not withstand, even just under suspicion. Thus, Mahong using this reason twice posed no problem, even if it was reported officially, no one could argue against it.
