You’re right, it’s pyrolysis.
I was unaware PTFE presents health risks to any creature; the fluorocarbon products given off by heating it sufficiently are dangerous to a variety of animals, though. For humans, this concentration is much higher than what is released by a properly-used nonstick pan, and to my knowledge, PFOA hasn’t been used as a surfactant in most (all?) teflon cookware for many years.
