In this case, the Court of Appeal in Amsterdam established that the employer has a duty to record the employee's working hours and that a failure to do so will result in relying on the employees own calculation.
the employer was ordered to pay for the overtime hours worked, but was also found liable for damage suffered as allowing such an amount of overtime to accrue was a lack of duty of care.
The employer's argument relied on the "exemption clause" included in the Working Hours Act, the legislation implementing the Working Time Directive in the Netherlands. The clause limits the applicability of the Act to employees earning no more than 3 times the minimum wage (as was the case for the employee in question). This raises an interesting point of debate as to whether such an exemption is in line with the derogations provided for in articles 17 to 22 of the Working time Directive. The topic was not addressed however as the Court rejected the argument that the employee should be exempted.
For the full text of the judgement (in Dutch) see here.