I have encountered this on a small scale. For my capstone project we are using InfraRed LEDs to illuminate the eyes with IR light. When we designed the circuit that will power the LEDs we needed to make sure that once it is all put together that the power outputted by the LEDs will not harm the patient using the product. Once we built the circuit and tested it we found that whilst the intended use was fine, when we went to a worst case scenario of all the current being pushed into one LED, the power would become harmful. Since it was capstone we did the correct documentation, but it is not like industry where much more rigorous documentation is required. IT still allowed me to appreciate the need for design verification and how it is very good to have. Because of our early testing we were able to see the issue early and were able to change our design earlier and stay on schedule.