There is such a lot of nonsense talked about this kind of stuff. Nope, I have not watched the video as like alcam, I find that guy super irritating.
Even if you had some kind of jobsworth police officer who decides that someone who has keys with them must be in charge of the vehicle despite not even being in it or close it and so could be charged with drunk-in-charge if he has had a few drinks, what is the likelyhood of that actually getting to a court case and getting convicted, especially in a Jury trial where the chances are most of the jurors will have had a drink AND had car keys in their possession with no intention to drive it.
What about if you are flying somewhere on holiday and you park the car, and have a drink in the airport bar say? Gonna get done for being "drunk in charge" if you have a second pint?