With the current status change report it is not reliable when being used to track a value such as a commission amount. This is due to duplicate status changes being counted as separate amounts towards the total value.
There should be a way to exclude these duplicates, either as a report option or by having a filter to include only unique lead ID's.
A workaround is available by using funnel reports and the 'lead value' or 'lead cost' default fields but it would be best to expand the capability to other reports like status changes and to accommodate additional fields.