A system for recording operation data comprising user operation data and vehicle operation data for a remotely controlled vehicle, the system comprising: a device for recording user operation data for the remotely controlled vehicle, the device being remote to the remotely controlled vehicle and the device comprising: a first memory configured to record user operation data, the user operation data comprising outgoing operation commands that affect operation of the remotely controlled vehicle, said outgoing operation commands received by the device from a remote controller of the remotely controlled vehicle and transmitted to the remotely controlled vehicle, and a vehicle operation data recorder configured to be included in the remotely controlled vehicle, the vehicle operation data recorder having a second memory configured to record vehicle operation data; the system being characterized in that the user operation data recorded by the first memory is inaccessible for modification; in that the vehicle operation data comprises incoming operation commands that affect operation of the remotely controlled vehicle, wherein said incoming operation commands are received from the remote controller of the remotely controlled vehicle; and in that the system further comprises a processing unit configured to receive the user operation data and the vehicle operation data, the processing unit including one or more processors which, individually or collectively, are configured to compare the user operation data and the vehicle operation data, to identify one or more discrepancies between the user operation data and the vehicle operation data, wherein the discrepancies include differences between the outgoing operation commands and the incoming operation commands, differences between the incoming operation commands and vehicle status data, and/or differences between the outgoing operation commands and vehicle status data. a device for recording user operation data for the remotely controlled vehicle, the device being remote to the remotely controlled vehicle and the device comprising: a first memory configured to record user operation data, the user operation data comprising outgoing operation commands that affect operation of the remotely controlled vehicle, said outgoing operation commands received by the device from a remote controller of the remotely controlled vehicle and transmitted to the remotely controlled vehicle, and a vehicle operation data recorder configured to be included in the remotely controlled vehicle, the vehicle operation data recorder having a second memory configured to record vehicle operation data; the system being characterized in that the user operation data recorded by the first memory is inaccessible for modification; in that the vehicle operation data comprises incoming operation commands that affect operation of the remotely controlled vehicle, wherein said incoming operation commands are received from the remote controller of the remotely controlled vehicle; and in that the system further comprises a processing unit configured to receive the user operation data and the vehicle operation data, the processing unit including one or more processors which, individually or collectively, are configured to compare the user operation data and the vehicle operation data, to identify one or more discrepancies between the user operation data and the vehicle operation data, wherein the discrepancies include differences between the outgoing operation commands and the incoming operation commands, differences between the incoming operation commands and vehicle status data, and/or differences between the outgoing operation commands and vehicle status data.