Gordon didn't make contact with headquarters in the conference room but took his cell phone and left to find a quiet place. Jimmy didn't know the people at FBI headquarters at all, nor did he know who or which department Gordon was trying to contact. However, the resources at headquarters definitely outstripped those of the Manhattan office, and whoever Gordon was seeking help from surely wouldn't be inferior to Gordon.
Not to mention anything else, the team of four people that included Gordon had impressive capabilities. Their analysis of clues, field investigation, and interrogation skills far surpassed those of Jimmy and Chris. As self-deprecating as it might sound, that was the reality. A team for which headquarters had specially arranged a helicopter transfer definitely comprised reliable individuals.
