So I researched and answered my own question and will post for others who might care
I asked earlier about the domino-falling (using one tree to knock down another). I found this on the WA State Legislature website:
Now my new question is this: What was so dangerous about that 16" DBH tree? Why would you use a much larger tree to knock down such a wimpy tree? I guess the smaller "danger" tree could have kicked back off of a log on the ground but AFAICT he had endless possibilities for escape routes. He was cutting on the edge of the cut block and could've just ran right into the standing trees.
I know the show is filmed in Oregon but thought laws might be similar.
On a snag falling job I do each year I drive a fair number of trees. These are usually in the 16"-30" DBH range. They are pines and firs. Snags don't fall like a live tree and in addition many are either limb locked or at least have limbs of several trees affecting the direction of fall. Plus the trees are close together and a good escape route doesn't always exist. Some of the trees are in soft sand and pull the root plate when they fall so sometimes I can drive with a tree in better soil. So I like to cripple the snag and then drive it with another.
I don't know for sure but I would bet more people are injured or killed with smaller trees, say up tp 3' DBH, than larger trees.