Well, I would like someone here to show that pre-knowledge of a hazardous condition on a property is the overwhelming pivotal factor when determining liability? Just claiming it over and over doesn't make it so. So, where's the proof?
Where are cases, for example, that when an air conditioning unit falls off a roof and kills someone below, that the property owner/insurance company are found not liable because they did not know the bolts were rotted through?
Pre-knowledge is not the overwhelming determining factor in work accidents, auto accidents or personal accidents. So where is the proof that it makes ALL THE DIFFERENCE in property accidents?
But I'll play along: I would argue in this particular set of facts that the property owner would be at least partially liable because AC units should be regularly inspected so it should have been caught unless it was a really sudden degradation in the bolts. If the bolts suffered from a manufacturing defect, liability would probably apply to the manufacturer as well.
OMG. I'm still waiting.
If an employee is hurt on a ladder the company knows is defective...voila!
If someone has an accident because their brakes were bad and they hadn't had them serviced/checked in years...voila!