What is "defect in and of itself, was a dangerous condition" in personal injury mean?

A toaster has a design flaw that allows it to short-circuit every tenth time the user tries to toast bread. The other nine times the toaster always works perfectly so the user never knows when the exactly the short-circuit might happen and start a fire. So, the toaster design flaw - by itself - makes the toaster dangerous. Not the wiring. Not the user. Not the warning. Nothing but the toaster design flaw makes the toaster dangerous. Said another way, the design defect in and of itself was the dangerous condition of the toaster.

I hope this helps.

Attorney Brinkmeier perfectly described the language in the context of a products liability case.

However, the question did not indicate the context. The quoted words sound to me like boilerplate language that I've read many times in the context of other personal injury cases like slip and fall accidents. For example, a plantiff's attorney (like myself) might put that language in the body of a complaint to tell the court that a broken curbing outide of a store "in and of itself" was so defective that it caused the plaintiff to fall down and there was no other possible cause of the accident, such as the plaintiff's own possible contributory negligence in not noticing the defect.

The idea is to allege a pure and simple accident 100% caused by the defendant property owner that is being named in the suit and leave it to their lawyers to challenge it within the short period of time in which an answer to the complaint is required. If they do not properly raise their defenses, then the plaintiff's case is much more simple, and whoever was responsible for the dangerous condition is fully liable to the plaintiff.