I think such issues can be avoided to an extent by a wearable device which can track your alcohol content or track if you are conscious. If at any point it detects you are not in control of you sense, maybe raise alarm, send alerts to friends/family etc. Maybe it will help in avoiding such incidents under the influence of alcohol or other drugs.

Netflix created something for fun to detect if you are awake or not: http://makeit.netflix.com/projects/socks . I wish someone creates something similar to save people from horrible situations.