Passage Summary: Since the only fingerprints found belong to the owner, the inspector assumes the thief definitely used gloves to avoid leaving any evidence.

Conclusion: The person who stole the diamonds must have been wearing gloves.

Reasoning: No fingerprints were found at the scene of the crime except for those belonging to the owner of the premises.

Analysis: The inspector's flaw is a failure to consider alternative explanations for the lack of fingerprints. While gloves are one possibility, the thief could have wiped the prints away, used a tool, or perhaps the owner himself is the thief. To find a parallel flaw, look for an argument that concludes a specific method was used simply because the most common evidence of an alternative method is missing. It's a bit like assuming a ghost ate your cookies just because you didn't see any human footprints in the kitchen.