But injury is different. If you stopped because you are injured, one can argue that by allowing you to continue they are letting you place yourself into more danger of getting hurt by being allowed to continue while injured. Either you are not injured, or are injured but it doesn't prevent you from completing the program - in which case it is your decision (and your health) if you want to risk it. But if you are so injured that you need to stop, one can argue that you should withdraw because you are putting yourself in huge risk of making your injury worse. If your injury is bad enough that you stopped, it should be bad enough that you should withdraw. The argument that you stopped because it was unsafe because of your injury, but then you suddenly continued (so suddenly the same injury became safe again) does not seem to make sense.