Using pronoun "it" instead of (personal) pronouns "her" or "him"

Can pronoun "it" be used instead of (personal) pronouns "her" or "him" in a disparaging/derogative manner especially in the personal pronouns?

I've watched a movie wherein a dead body was found and, without saying anything, they've been told just to "burn it!". I know this could have been strictly referring to "a body" — a neutral noun. However, the "burn it!" was said in a really disparaging manner.

And let's suppose that the man who said it knew the man who was killed. Still, can we use "it" instead of "her" or "him" in that manner emphasising the hate and scorn towards a particular person?

There's a difference between a dead body (a biological object) and a dead person (the character). "Her" and "him" (as well as the gender-neutral singular "they") are usually reserved for people. So, the dead body isn't a person; that's why it is referred to as "it".

So, if you use "it" to refer to a thing then you imply it is not a person. That's factual rather than disparaging if said thing is an inanimate object (e.g. apple, Earth, dead body) but it is derogative if you refer to a human being. If the man who said "burn it!" was referring to a character rather than to a lump of flesh and bone, then it would be derogative because he was denying the character's person-ness and effectively saying they were an inanimate object.