The light source for the headtorch is misplaced fowards (I am currently running the stable version of 1.0 update).
What happens is when you put the headtorch in your head the light source is a meter in front of your face, instead of being in your head. This isn't noticeable visibly and it looks like it is working correctly, but if you get close to a wall the source for the light will go through the wall and illuminate the other side instead of illuminating the room you are in. (This should be more clear when looking at the screenshots provided). The practical effect of this is that it is very annoying to walk inside buildings because your headtorch is constantly going through walls and you end up in the dark. I have tested to see if this effect also happened when the headtorch was in your hand (as shown in the screenshot), but it appears that it works fine in your hand, so the problem only occurs when putting the headtorch in your head.

light source before going through wall:

light source went through wall and is illuminating the corridor, but i am in the dark:

testing the headtorch in my hand very close to a wall and it appears everything is working as intended when not in the head: