We are all glad he failed and though you have your opinion (which I respect) neither of us know what was going on in his head.
On the other hand, I'm sure you would agree that to even contemplate such an act was not the product of someone that was thinking correctly. To carry it out even prooves the fact further.
Therfore, imho someone who's mind snapped.
Unfortunately we will never know what finally caused him to carry this out