After the radio announcer states that the radio program is shorter due to technical difficulties, Max takes the gun from the dead engineer Hammerstein. After 99 states Hammerstein is the KAOS agent, the gun appears back in Hammerstein's hand.
Hannibal Day accuses Ms. Hickenlooper (the organ player) of playing a major seventh (M7 or Maj7) chord in the closing theme "last night." This is presumably when Max, the Chief, and 99 are listening to it in Max's apartment. There is no audible major seventh chord in the closing theme.