I'll be a voice of dissent here and say that I've smelled human and animal decomp and I find it's very situational. I don't always peg it as decomp right away, depending on the environmental factors. It's kind of one of those things where if I know it's a body I'm like, "oh yeah, of course!" but I wouldn't necessarily always be like "something is dead here." I do think it can smell like rotting trash.

And I mean, the reason I've smelled it so much is because I'm a cadaver dog handler. We regularly use rotting food specifically to train our dogs against distractions because the smell can be kind of similar, and dogs need to learn to differentiate between a rotting chicken leg and a cadaver (also to just not eat the rotting chicken leg because dogs are gross, but you know).

I find it really believable that people who were smelling this random bad odor wouldn't be tearing things apart looking for a body and instead would be like, "Damn, we gotta stop wasting so much food, the trash can reeks," or whatever.