I think I've said that before lol.....Not only can a dog smell drugs in a gas tank, bombs in a suitcase, people under 10' of snow, now they can smell cancer in a human body. Coyotes have even better sniffers then dogs.
You have to take alot of things into consideration when dealing with coyotes. #1 always expect the unexpeced because that is usually what happens.
Some coyotes have never smelled humans before or are young and don't relate human smells to danger, most coyotes know better then that.
I've called and howled coyotes right to my truck day and night, I've been told they are scared of trucks?
I've called in a coyote and killed it....another one came in the same way and was smelling his buddy, he died too......Then a third one came in and smelled the other two and he died. You'd think they would be smarter then that.
Bottom line, you're never 100% sure what any predator is going to do.