Possible Clues:

• Incredulity
• Refusal to give credit?
• Lack of faith
• Detective's theory produces doubt
• Refusal to accept as true bids I feel flawed
• More than mere doubt
• ''I'm shocked'' reaction
• Doubt detectives contradict sheriff, ultimately
• Fibbed half-heartedly, with lies perhaps generating this response
• Lack of faith shown by Delibes, I suspect, before start of fugue