When your scout leaves so do all the scout reports, simple. Although, for example..... You have Fernando Gago on your shortlist, your ex-scout does a scout report on him, then he leaves. He hire a new guy and he does a report on Gago too. In the top right hand corner when your are viewing the report you can switch through the different reports, this will show the report your old scout did too. But all match reports are gone. | 
