While I feel for the property owner, I guess I don't see how it's different that any other 'act of God.'
If the neighbor's tree falls, in a storm, on your house, car, trailerable boat, then it becomes your problem. This is one of the reasons that we have insurance.
If the damage is caused by someone's negligence, then there is fault. Again, however, this is why we carry our own insurance to protect from this situation as well.
As PR was mentioned early is thread, the situation on the ground is still a royal mess. Most of the islanders (about 80%) still do not have power. A greater immediate health concern is potable water. The official published number is that 75% have water, but that is grossly over-inflated, as this is access to water, not actually having water at their houses. Access means that you can drive your car (if you have one or it still runs) and bring home the water you need. Makes it hard enough to get water from drinking, cooking, and flushing the toilet. Makes it really hard to have enough water to bathe or wash clothes (and remember the storm was more than 5 weeks ago!) Really hard to do if you are elderly or disabled.
In Aguadilla, on the northwest corner of the island where my in-laws live, there is NO electricity, NO running water, and spotty cell-phone service (kudos to AT&T for setting up some mobile cell towers) on the island.
I believe that the situation in the USVI's is equally as bad.
This being on an island thing is hard. One can't just hop into their car or truck and take supplies or drive loved one's home. State-side it is difficult to even send supplies. There currently is no way to send something like a generator unless you have your own plane. Shipment by USPS is also far from normal. The shipping of packages (even priority) takes a minimum of 21 days, if the packages even get there as many are being lost of pilfered.
My wife and I are going down next week for a couple of days to check-up on my in-laws in person. Both are in the mid 80s (he is a Korean war vet). While from a property standpoint they were fortunate there was no major damage (concrete house with concrete roof), we are concerned about their health. We have purchased (2) one-way tickets to bring them state-side for a while (kudos also to Jet Blue who capped all ticket prices from the day after the storm until November 15th!)
Jim