Rick:
I am a lawyer, and over the years have done a fair amount of products liability work, primarily representing manufacturers. So, let me state based on about 30 years experience: "I dunno." /forums/images/graemlins/tongue.gif
Certainly we are in a litigious society. The law regarding the duties of a manufacturer vary from state to state, so my following comments are general, at best. There are several theories of law on which a manufacturer may be held liable. The most common in modern litigation is the concept of strict liability in tort. The essence of that body of law is that a manufacturer is liable if a product is defective when introduced into the stream of commerce, posing an unreasonable risk of injury, and in fact causes the injury complained of by the user. The defect can be in the design or manufacture of the machine, or in the instructions or warnings provided with the machine.
The lack of extensive instructions with Power Trac machines certainly could be argued as rendering a machine defective if an owner or other user does something with the machine that causes harm. The resulting suit will contain issues as to whether instructions or warnings were needed, whether any instruction or warning would have prevented the injury, what the wording of an adequate warning might have been, etc. In most jurisdiciotns, experts would testify on both sides, and a jury would decide whether the machine was defective and whether the defect caused harm. Misuse of a product generally insulates the manufacturer from liability unless the misuse is forseeable and not instructed or warned against.
There are also legal theories involving claims of breach of warranty - either written into the contract or required by law - and claims of negligence by the manufacturer. It is an oversimplification to say that the proofs and issues under the separate theories are the same, but often all three will be claimed, and the facts to be proved are whether or not it was a good machine, and whether instructions are needed or, if provided, whether they are adequate.
Despite the suits that get wide publicity, manufacturers do not automatically lose lawsuits. I haven't seen statistics recently, but I suspect that fewer cases are actually brought to suit than you might suspect based on news reports, and the majority of plaintiffs lose or receive minimal settlements. Moreover, most manufacturers of any substance carry sufficient insurance to ensure that they will be defended by capable counsel if they are sued, and the insurer will pay any judgment which may be entered. Obviously a manufacturer could be destroyed by a string of litigation losses, but should generally be adequately insured to withstand even a significant loss in court. I have no idea what coverage PT may have, but certainly hope it is adequate.
The best defense against products liability claims is to make good products. Although I agree with Paul that I'd like some literature with the implements to advise how to service them and when, I really haven't had a problem figuring it out other than the location of a stray zerk fitting or two. I haven't had any problem recognizing reasonable limits for use of any of the implements. For instance, my posthole auger can tear someone's arm or head off and I don't need a book to tell me that. If someone is injured, will a jury conclude that the operator needed written warning not to engage the machine with a person close? I hope not, but if it happens, that's what the insurance is for.
So, I don't think anyone can answer your question. It was refreshing to me to find a manufacturer who expected me to have tome intelligence and common sense, and when I hit my head on the canopy in their shop, they didn't go into apologetic spasms - Terry said: "You'll learn not to do that." Although I haven't completely learned, and still hit it occasionally, I do appreciate Terry crediting me with that much intelligence.