Here's the thing: as others have posted, a million dollars of liability insurance for tractor operation costs about $800 a year. Insurance companies are in it for the money, and they know risk, so the price of insurance tells you all you need to know about the likelihood of something happening. If they're taking in money by the hundreds and potentially paying out by the millions, they thing they're insuring against has to be incredibly rare. That doesn't mean it never happens, but it's not going to be common.
Secondly, most lawsuits are settled, and most settlements have confidentiality clauses. So most people who have been involved in lawsuits aren't at liberty to discuss them. Only a fool would risk losing his insurance coverage by discussing a settlement, even under an alias on an internet forum.