Take this scenario : Tom is part of the Sales hunt group, and spends his day answering calls coming into the main sales number (hunt pilot). He also takes two personal calls. At the end of the day a manager pulls a report for Tom, but the only thing listed are the two personal calls he took. Sadly, this is the default behavior of Cisco Call Manager. CUCM will not correlate these calls into the Sales hunt group with Tom because (in CUCM's opinion), these calls were not to Tom.
Luckily, Cisco has given us a way to change the default behavior. We'll need to change two service parameters inside of Call Manager
Now, going forward, hunt group calls will show on the end user's report in VoIP Detective, and the meeting between Tom and his manager will go much better.