I too flew the Mohnesee "bombing run", as many did. Due to the terrain, even in a helicopter at 140 kts it wasn't easy to get the height down to the required 60' by day, let alone by night. How they did it in a heavily laden Lancaster while being shot at.....
We never heard any comeback on my slight indiscretion. Nor about our later one at the Edersee when more than one aircraft had to land when caught out by freezing fog, but that's another story.