I've thought of some ideas that would excuse someone of having no other choice but to HO,I have only a couple, but if you can fill in, more than welcome:
1. your in a 1v1 and your having a good fight with this guy. Some picker comes in tries you. Your slow enough to fall out of the sky, but you have one good shot, and it becomes a HO shot.
2. your in a 1v1 and the guy continues to HO you, but you don't HO back, until you get sick of it and wile he has more E than you, you take the HO shot.
3. HOing when you have a vulched field to stop the vulchers
4. When your being ganged (more than two)
Any other reasons that would make a HOing rule exceptional?