I have no idea why he says the key of the song is F because, in fact, it's in E flat. I know this because I play piano and I have played along to the original recording in E flat. This is strange.
Parts of Monster sound like Michael. I will admit that the part you mentioned does sound very much like Michael, however, the part a little before it, 'why are you stalking me'. That doesn't sound like him at all, sounds forced. Sounds like someone trying to sing it in a way that Michael would.
The word 'monster' in the verse doesn't sound like him. The 'mama say mama got you in a zig-zag' part doesn't sound like him (although I do like that part). Also, the breathy way he finishes notes is the exact same way that Jason Malichi does. The entire bridge before the rap sounds ridiculous, the 'eat your soul' part kills me. I feel like shaking whoever hears these parts and doesn't question them seriously.
Impersonators are good at imitating voices which is why some parts would sound a lot like him, but they are never perfect, hence the flaws. If this were really Michael I don't think I would be questioning as many different parts as I am
