Yamaha RJ15 accident concealed, lawyer and reviewer ?

Moin dear people, recently got me a rj15, my first motorcycle, and was yesterday at nem r6 speckumpel who then unfortunately showed me that the machine definitely had an accident, although she was insured as accident-free. do you have experiences in the purchase of private and such incidents? my knowledge now I will visit a lawyer on Monday and let me be advised. salesman says of course he didn’t know that and that would have happened to me now in the 2 weeks as well in. many thanks in advance and a nice weekend