Trivia: When Clouseau spins the globe in his office after the first interrogation of Maria, the part calls for him to catch his hand. Peter Sellers ad-libbed a line about Africa being all over his hand. Just before the dissolve to the next scene, the actors start to grin at the ad-lib. (00:35:45)
Trivia: Maria (Elke Sommer) cannot refrain from laughing at Peter Sellers' antics during the interrogation. She is trying to stifle her laughter. (01:31:40)
Trivia: The "synchronize our watches" dialogue was improvised by Peter Sellers and Graham Stark.
Answer: In this particular film, he's referred to solely as "Commissioner" and is then Chief Inspector in every subsequent Pink Panther film in which he appears (up until "Son of the Pink Panther" [1993], Herbert Lom's last appearance in the role, when he is again Commissioner). If you're after a reason, there likely isn't an official one, though perhaps Dreyfus's murder spree and mental breakdown in this film led to his demotion.