There's multiple warnings about acetaminophen in this thread, even. I hope he's fine, yeah, but that's what happens when you screw around with drugs without knowing what you're doing. It's stupid.
It appears he posted his last message right after taking it, and I know he got the message within a few minutes of that. If he called the hospital within the hour (and if he didn't, he was just being stupid again), that's plenty of time. I wouldn't worry.
But then if he does die, we'll probably never have that confirmed.