Jack was also paying close attention to the recent changes inside Golden Port City. He had heard some rumors, mostly coming from people connected to smuggling groups.
It's just like... some people complain about work-related matters to a stranger.
They don't believe a stranger would cause any issues in their work or life due to their complaints.
Just like when you're waiting for a bus and casually chat with a passerby, you tell them a lot of bad things about your boss without worrying they'll pass it on to your boss.
It's the same at customs. Sometimes the people who bring money would complain to the officers, lamenting that Lance's family's methods are somewhat overbearing and inappropriate.
Then they would convey these complaints to Jack.
Few people knew about Jack's relationship with Lance, and his promotion to customs officer wasn't handled by Lance directly, but Arthur took him to sort out the promotion issue.
