Only referencing America, but professional liability for doctors, engineers, lawyers, etc isn't based on perfection. It's based on a reasonable effort.

So Google could, for example, switch from a tiny "this could be wrong!" byline to having the AI be less overconfident every freaking time regardless of whether it's spouting made up crap or actual facts.

The scale doesn't sound like a way out. If your company expects to get away with doing the wrong thing where smaller companies can't, then the solution isn't to continue getting away with it.