He should have dropped his weapons and hidden them without the police seeing it and then mention he’d climb down, and then make some excuse like “sorry pals but I have a date at Ninjastreet number 9b” and the police will say “this is Ninjastreet 19b you idiot”
And he can tell them: “okay that makes sense because I knocked 3 times like I was told”
After that he just ask which direction 9B is, and then he runs away or something, to later retrieve his weapons
Couldn't have said it better myself
