Zenima pointed out your post for me and when reading it I can see there are a few things in my addon I will have to look over. The intention is for it to behave exactly like expected, but one thing I overlooked was that some addons expects UnitHealth() to show the post-event value. As you posted, waiting until last handling the combat log events would be a very clean way of fixing this. I will see if I can come up with a reliable way of doing this.
Pretty bad my addon is ignoring some damage. One more thing on the list to fix.
As for the generating additional UNIT_HEALTH events it's intended and necessary for the addon to do what it's supposed to do. UNIT_HEALTH events are only generated whenever the health of a unit changes which really is the expected behavior. There really isn't any way of generating fewer UNIT_HEALTH events without slowing down the update rate of health bars and such.
Going to change how it hooks as well.
Although I have a good bit of experience with programming in general the lua language was new to me when I started out on this addon, I learned lua to make this addon after coming up with the idea. Your comments have been helpful and very much appreciated!