How can a coroner rule a death "Homicide", but not be able to give the cause of death?

Sometimes you can rule out natural causes and by the circumstances of how the body is found, it can presumed to be a homicide, even if no cause of death is known.

What if they found you in a giant blender. They can tell it's you from the DNA. The method of disposal means it's presumably foul play. There's no evidence yet how you actully died.

But, true enough, sometimes bodies are disposed of under suspicious circumstances even though the death was innocent. They usually deduce that it's homicide based on the circumstances. A coroner is part doctor, part cop.

There is some judgement involved. It may have been clear that the death was not by natural causes, and if the circumstances seem to indicate that there was foul play, the coroner may rule it a homicide (which, legally, simply means one person killed another, without judgement as to the appropriateness of it).

A bound body in a shallow grave pretty-much rules-out suicide, accident, and natural causes.

Homicide is defined as someone killed them. The exact cause is HOW they were killed. Such as strangled, poisoned, shot, so forth. The tape made it clear someone had part in the killing... but no proof what they did. Obviously, it could not fit any of the other 3. If an accident, it would have been reported...not a body hidden in the woods.

They ruled out the other three. Obviously not natural given the condition of the body; not suicide given the age of the child; not accidental because of the condition of the body, where it was found, etc.; therefore, only one option left.

If someone is found crushed to death in a parking lot, was it the collapse of their skull, or the collapse of their chest cavity including their heart that caused their death? I think we can rule out suicide and natural causes. Give us the cause of death, please.

Say you find someone drowned in a pool. They have duct tape over their mouths and have been pumped full of a heavy narcotic that could have stopped their hearts.

You know there is foul play. Nobody naturally ends up like that. However, it could be difficult to determine whether they drowned or their heart stopped.