For someone to be criminally liable you have to show that they knowingly recorded somebody without their consent. An accidental trigger would definitely not qualify. For them to be liable civilly you'd have to show that you suffered some harm from the accidental recording and that they were negligent in allowing it to happen, and I have a very hard time believing that there are many situations where that's possible.
California's law specifically states that a beep is sufficient to establish recording notification, so that one is out; Florida's law requires intention; as do Illinois, Maryland, Massachusetts, New Hampshire, and Pennsylvania.
Washington is the only state where it isn't totally 100% clear, and the law seems to read that a tone would be sufficient to establish consent.
