Wiley is talking about Head-On attacks, as in one at the merge of two aircraft, and there simply is no unavoidable Head-On attack.
There is no difference between a head-on attack at a merge with similar aircraft and a head-on attack between a disadvantaged aircraft against a superior one - a head-on attack is a head-on attack. Any classification otherwise is an attempt to justify one's excuse of how they wish to fly. The only differing factor is the appropriateness of the attack based on established ACM doctrine.
It's identical to saying that turning in the vertical is "turning" because it isn't horizontal. Turning is turning is turning - how it's employed doesn't change what it is. Stating otherwise is an arbitrary excuse based on a lack of knowledge and experience in ACM.
Front quarter shot isn't a HO. A HO is both planes in the cone of fire of the other. What you're describing is the guy in the spit almost turning hard enough to get his guns on, but not quite. That's not HOing, that's 'getting beaten'.
Wiley.
No, consider a 190 is being roped by the Spit. He can't turn away, or he'll present his six to the enemy. At the same time, he's saving as much E by trying to reduce the angle of his climb. The Spit is above, but slowing quickly. As the Spit's nose drops, the 190 has two choices - pull up and take a head-on shot, or avoid the shot and subsequently lose all positional advantage. Given this scenario, the only wise choice for the 190 is a hot remerge. The Spit will get hit either way, so the wise Spit pilot will take the shot as well.
This results in an unavoidable hot merge/remerge, as the shot is the only advantage the 190 has.