The "solution" is easy, but additional setup reduces adoption. When adoption is harmed by lack of safety they will rapidly address it to still be able to hear everything that happens in your car, home or wherever your phone is. In here, they will just make you add a voice fingerprint. Just like your thumbs have a unique pattern so does your use of voice. This way, they will block things like this injection, and they will also have a HUGE benefit: they can record and transcribe not just what was said ir heard, but also who said what. While there may be stronger and weaker implementations of voice fingerprinting, this is so the case with any other security mechanism. And very quikly Facebbok may have an edge, as these ID features become socialized: ej. You coukd create a fingerprint, and your friends may give you rights to do some functions while on their property. Say "open the door once", play music (if in a party). So this "authenticator" will be able to track a person's actions across ANYTHING that listens. Scary? It's kind if the same as in authenticating using Google for third party services, or giving apps (or friends) some rights. The only thing that can slow down adoption or challenge this scary future (too much power and an eye and hear following every person all the time) is when we start hearing actual cases of abuse of this power. At sone point the privacy issues will lead to the creation of new political parties, but in general you'll learn to live knowing anything you say or do will be recorded and proccessed in realtime for profit or power.
BK is only guilty of opportunism and accelerating voice fingerprinting for house-hold / consuner use.