So just how was the whole time loop possible to begin with? Hector 1 doesn't come across the time machine until after he has seen the woman in the woods and was stabbed. And in order for that to have happened, he would have had to use the time machine to set the situation up to begin with.
Riddle for the Ages: Was it really physically impossible to change the past or Hector actively prevented himself from doing that by following the advice from the scientist? Though the two options are not necessarily mutually exclusive as the advice itself could be caused by physical immutability of the past in the first place (adhering to Novikov's self-consistency principle).