Yttd has such good commentary on cops. They aren’t the good guys, they aren’t goofily incompetent. Each one is portrayed so differently. They’re seen to the other characters as heroes, protectors of society, but only those in the force have the privilege of realizing that isn’t true firsthand because they do the work. Mr Policeman was able to leave before he was able to do something he regretted but Keiji grew up believing in this system. That they were heroes who protected people. And he willfully looked away until it was too late. Megumi is the idealic cop. The top dog. She cuts deals, she’s shady, she quietly fires people who threaten to expose scandals. Yet, even after Keiji quits and even with how much he despises the force and what it represents, he still tells the cast he’s police because he knows that will make him trusted because he’s learned that no matter how shady he is, people will gladly let things slide if it’s an officer of the law.
I've never seen anyone referencing other than the bar scene or the time Mr Policeman mentions how is gonna be his son named. However we have this dialogue where Keiji says something about losing a person you respect, and Joe's reaction is the same as the one he had at the bar scene with Gin (he reacts speechless in both scenes at first).
Besides, Mr. Policeman wanted to be a person his son would respect, as it's stated in Keiji's memories.