Reset statistics if Experiment results are cached, but Experiment is reset from the admin interface

In the case the Experiment is reset from the admin interface, its cache files are not erased (they cannot since we don't know if they would be shared by other experiments). If the experiment is re-scheduled, the scheduler will not run a single block since all files are cached. When replying to the webserver, the scheduler will indicate successful completion, but no statistics, stdout or stderr will be present.

At this point, the web believes these are empty. Instead, it would be more correct if the backend would try to re-connect old statistics to the experiment instead.