Tension roller of the timing belt-1.4 petrol engine

Hello friends of the Alukugel, on the 1.5. on the highway at approx. 150 km/h without any warning the lower tensioning roller of the timing belt said goodbye! The plastic jacket of the camp split into two parts! Luckily the Plunder has wedged in a corner of the timing belt cover and did not get into the belt drive. So I was still able to drive home unharmed. Has such a thing happened already? I think that is such a bad quality that not even 80 Both timing belts, on the other hand, still look almost new, as well as the upper tensioning roller, which also has a plastic mount. I photographed the whole time. In the picture on the left the upper, on the right the lower roll. Greeting hoschi3