I don't think PF has killed a human before, but I think he's spent an unhealthy amount of time speculating on it and more importantly, on body disposal. I think the reason he got sick to his stomach in the wee hours of Thanksgiving morning was because he had been stewing on this for so long and he had come very close. He was probably afraid and raging at his own cowardice* at the same time.
* Cowardice when it came to actually doing it himself and cowardice at the fear of being caught. What scared him more - fear of LE or fear of SF?
* Cowardice when it came to actually doing it himself and cowardice at the fear of being caught. What scared him more - fear of LE or fear of SF?