[Pseudoscience-is-malarkey (OP)]

Here in the U.S., as well as Canada, the U.K., and most of Europe, if a man hits his wife or girlfriend, etc., the man will only go to jail if the woman presses charges, or the attack is caught on film, or seen by a reliable witness. Even if the woman is black and blue. The cops will take the woman away if they feel medical attention is needed, but that is usually the extent of it.

[Colin2B]

This situation is true of any assault. If the victim will not testify then in the absence of witnesses the prosecution does not have a case to take to court.

[alancalverd]

Absolutely. In the absence of a testable testament, the police would be presuming and asserting the identity and motive of the assailant - and even that it was an assault. Unsupported assertion is inadmissible in a civilised society. Unless the person making the assertion is an unqualified HSE inspector - but that's a different law.

[Bored chemist]

Unless the person making the assertion is an unqualified HSE inspector - but that's a different law.

You never did say what happened when you took that idea to court.
(Possibly because all the inspectors are qualified.)

[Bored chemist]

Even if the woman is black and blue.

That suggests that an assault took place, but doesn't say by whom.
Are you proposing to abolish the presumption of innocence?

[evan_au]

Could the Police call Siri, Alexa or your Smart TV to give evidence?

All these devices have voice recognition, but for privacy reasons, the vendors will be very keen to say that these devices don't record anything unless called...

I have heard of teachers in a classroom telling off a kid, only to have Siri say "I didn't quite catch that..." - at which point the whole class fails to get the message, too.

[Bored chemist]

Could the Police call Siri, Alexa or your Smart TV to give evidence?

No.
Fundamentally, because we can't threaten Siri with prison for perjury.