Yeah, it's not from overheating. If it got hot enough to bend the shaft, your paint would be bubbled and the l/u case would be discolored, as well as the shaft itself being discolored. You may have hit something. People hit stuff all the time and never know it. I know of guys that get back to the ramp and their skeg is gone, or their prop is banged up and "they never hit anything." It happens. You got insurance? I'd approach it through insurance before I went through Yamaha.