The man might have had something to hide from the police, like being involved in illegal activities, which made him hesitant to report the robbery. Reporting the robbery could have exposed his secrets or led to further investigation. He might have decided that remaining quiet was the lesser of two evils.

The man might not have reported the robbery because he was scared of retaliation from the robbers. He might have feared for his safety or the safety of his loved ones. He could have thought it would be safer to stay silent and avoid drawing attention to himself.