Ok it does happen. I have a young friend, dead now, who spent 6 months playing video games and drinking beer. Nothing else, just those two things. Slept on the couch with the controller dangling from his hand. Died of liver failure. What do you call it, if not addiction?
First off, what was he really addicted to here, the video games or the alcohol? My girlfriends father died this past Spring because he holed himself up in his apartment, drinking himself to death and also died of liver failure. He would just drink and watch TV all day. In your case, I would call the video games incidental to the alcohol addiction just like I would call the TV binging incidental to my girlfriend's father's addiction. I'm sure there is a larger mental-health component to it all, but in the end, video games were probably not to blame here. And sorry to hear about your friend.
Surely you can get addicted to video games, though I have a nagging feeling that rate of addiction is lower than any of your classical addictions like alcohol or narcotics. Of course I also recall reading an article about some poor kid in Korea dying after constantly playing video games and not sleeping or the case of the parents who neglected their own infant who later died due to their supposed addiction to video games. So then you have nicely packaged stories of "that one kid" or "those parents" in your head to pull up at a moments notice and the wonderful forces of logical fallacies cause some folks to think it's an epidemic of never-before-seen proportions.
The point is that more "video game addiction" is just sensationalist bullshit. My mother surely thought I was addicted to video games in my teenage years. Of course I spent maybe an hour or two playing video games and the rest programming. In fact, even after I got a job as a software engineer right out of highschool and a full-ride scholarship, she was still convinced I was addicted to "those damn games" and I'm sure half of the folks here will one day be thinking kids are addicted to their Google Glasses or whatever technology we wind up with. It's no different than parents of yore thinking Rock n' Roll was corrupting their children. Parents, as a whole, can be some really sensationalist dumbasses.
Its hard to tell which was the 'greater' addiction - both surely were compulsive behavior which he couldn't shake. So its not right to call it sensationalist bullshit - I understand you want to protect a favored activity.
I'm not attempting to call your friends death "sensationalist bullshit", let's be clear on that. I'm calling the overall trend of people picking some new technology/activity and portraying it as the end-all sensationalist bullshit. I'm not trying to protect video games, I've long since stopped playing them. I'm just trying to approach this from a more realistic angle.
If you want to be in denial and not recognize a friend's addiction and mental health issues, that is understandable but a bad path to choose. I've seen addiction time and time again. I don't know your friend, it's possible he was addicted to video games and just drank a Heineken here and there and that the alcohol was purely incidental to his demise. However, I've seen this type of thing happen on several occasions. Someone has an addiction, be it alcohol, cocaine, or heroin. They lock themselves away from everyone and indulge in their habit. As a side-effect of that, they wind up doing something fairly low-energy like watching TV, surfing the internet, or playing video games. Ultimately, their organs start to fail and they wind up dead or near-death in the ER.
I've been to the funerals, I've seen the jaundiced, malnourished bodies, I've had to help clean up the aftermath, both emotional and physical. I'm sure your friend was a good guy who couldn't shake his problems, and I don't mean to make light of anything. I've seen too many otherwise good people die of substance abuse, and I know several members of my family will likely still die in a similar manner. Saying someone died "as a result of playing video games" is a cop-out for not wanting to admit someone had an addiction to other substances, whatever the reason may be. Your liver doesn't fail because you played too much Halo. It's sad, but it's the truth.