Well, there are lots of different throws, some are most likely to put somebody on their back first, others are more likely to put them head first into the ground. I would still agree with those that say most throws have a high damage potential against the untrained. And many throws can be altered slightly from safe training to be a lot nastier. For example, the basic tomoe nage can be really dangerous just by not releasing your collar grip. This will almost insure that you plant their head to the ground first.
However, adrenaline and drugs may cancel out a lot of pain, as is the case with any techniques used in self defense.