It's the classic "N guilty men" problem, aka Blackstone's ratio: if you risk putting one innocent person in jail, how many guilty people you need to catch to make it morally justifiable? 5, 10? 100?
You have to pick a number, or else no kind of criminal justice can exist.
It's more likely that a fall (or being thrown) would cause the symptoms.
In any case, these situations are extremely rare, much more than those involving any kind of head impact.
If toyota cars unintentionally accelerate and kill people, but sometimes people mistakenly accelerate and kill people. If I am driving a toyota and accelerate and kill a person, if 100% of all cops/investigators believe the first case doesn't exist, and the second case is the only possible answer, I will be thrown in jail without a second thought; my life is destroyed, and it wasn't even my fault.
But more than that, we don't even know what the ratios are, is it 90% / 10%? is it 10% / 90%? is it 50/50? Because everyone believes it is 0%/100% we can't make the "N guilty men" decision at all, so we need a hard stop, evidence, and re-start.
I know you were downvoted, but I think your thoughts are exactly the problem I am trying to point out. So thank you for commenting on it.