I just thought of this, and it might be evidence that WHH.
In season 4, we see that Michael cannot die until he serves some future purpose. He tries to kill himself and it doesn't work. While aboard the freighter, Keamy tries to shoot him in the face and the gun jams every time. Not much later, we learn that Michael has been kept alive by the universe (or island) so that he can keep Keamy's bomb from blowing up the freighter with Desmond on board... right? I mean, Christian does tell Michael that he "can go now" right after this so we assume Michael dies here and that delaying the freighter bomb was his future purpose.
Ok... so the universe had to make a gun jam so that Michael wouldn't die so that Michael could stop a bomb from going off for a few extra minutes? This leads to a huge question:
WHY DIDN'T THE UNIVERSE JUST DISABLE THE BOMB INSTEAD OF THE GUN????
This doesn't make any sense. Why would the universe go through all that trouble to make sure Michael can't die until this point when it could EASILY (as we've seen) stop the "firing mechanism" (a bullet is like a miniature bomb) of the bomb on the freighter without Michael being involved at all? Why would the universe intervene 3 times when it could have intervened only once?
This seems like minutia, and it could be just a writing device to make that one episode more exciting at the expense of the overall story... BUT...
Could this be evidence of WHH? The universe won't even allow you to throw a pebble into the river at all in the first place? If Michael dies when Keamy shoots him and the universe instead makes the bomb not go off right when Keamy dies, that would just be a pebble then right? The end result is still the same in that the helicopter lands and picks up Desmond and then takes off and the O6 are rescued, but the universe DID NOT even allow a pebble to be thrown into the stream AT ALL here.
The only possible answer I can think of, and this may poke a hole in this, is that Michael had to be alive to make sure Jin didn't die in the explosion... But that is stupid too because Jin SHOULD have died in that explosion, so we're lead to believe that the universe didn't let him die.
Alright, I guess that's it. I invite you all to have a field day tearing this apart. It's not a great theory of everything or anything like that but hopefully it gets the community thinking about this peculiarity.