Character Analysis
Lt. Collet of the DCPJ is just about the most perfect second-in-command ever. (Emphasis on the "just about" part.)
Even though he doesn't always see eye to eye with his superior (the legendary Bezu Fache), he respects his methods and typically is pretty loyal to the mission. He sometimes suspects that Fache is too hungry for the power and glory associated with his role as Captain, but Collet doggedly pursues his man and obeys orders…most of the time:
Having disobeyed Fache's direct orders and lost Langdon for a second time, Collet was grateful that PTS had located a bullet hole in the floor, which at least corroborated Collet's claims that a shot had been fired. Still, Fache's mood was sour, and Collet sensed there would be dire repercussions when the dust settled.
(70.3)
Can't you just picture his hangdog expression? He had finally decided to seize the day but colossally failed, and now he's back to moping (and mopping up the mess he caused) behind an angry Fache.
He goes on to totally redeem himself, though, by supporting Fache at the end when he could've been an opportunistic jerk and thrown him under the bus in front of the press:
"Lieutenant Collet," a BBC reporter said, her voice accusing. "Last night, your captain publicly charged two innocent people with murder. Will Robert Langdon and Sophie Neveu be seeking accountability from your department? Will this cost Captain Fache his job?"
Lieutenant Collet's smile was tired but calm. "It is my experience that Captain Bezu Fache seldom makes mistakes. I have not yet spoken to him on this matter, but knowing how he operates, I suspect his public manhunt for Agent Neveu and Mr. Langdon was part of a ruse to lure out the real killer." […] "Whether or not Mr. Langdon and Agent Neveu were willing participants in the sting, I do not know. Captain Fache tends to keep his more creative methods to himself. All I can confirm at this point is that the captain has successfully arrested the man responsible, and that Mr. Langdon and Agent Neveu are both innocent and safe." (103.24-28)
Collet knew Fache'd been gunning for Langdon and Sophie as guilty suspects all along, but his loyalty won out, and he publicly supports Fache. Good move, Collet.