Ask accident insurance and consequences

Servus @ all I want to know what you mean about it in asking accident insurance and consequences. A buddy of mine wants to tow his VW Passat combo with a car transporter from A-B to fix it together with me, so I got him the car transporter from my boss, and a friend of his has provided him with her car under the condition that she is driving along, now it came to an accident because the trailer with the car got into slings, injury wurd e no one! the damage to the towing vehicle C-pillar Complete in rear axle crooked trunk cover also broken, car transport is also scrap looks like a banana, and the passat also got a lot, So now following situation The passat and the towing vehicle are both admitted to the said girlfriend! The accident causer has not been registered as a driver, the towing vehicle should not have pulled the towing vehicle MAX. 750Kg and the trailer alone had already 800kg and the Pas sat also good 1800kg now what must now expect drivers and holders? Policyholder is at the DEVK with TK we please leave out their irresponsible behavior, brings now nothing more