When a DID routes to a Ring Group it simply shows it shows the ring group number and status answered, I can’t tell which extension actually picked up the call.
In the newer 5.x version you can click on the system link and get more detail but in the older 1.8x doesn’t provide that reference information.
There is additional information in the CDR when you hover the mouse over the destination. You can get the answering channel from the ring group this way.
As I mentioned you can get the info from SYSTEM column in newer versions, and none of the version that we run have additional information in the destination column.