I didn't see anything to suggest dictating or imposing anything about what he should do, simply concern that the behavior is unhealthy and could be damaging.I don't personally think it's right to dictate when someone else needs help or what they're doing is unhealthy. Leave that for them to tell you.
You can look out for friends but you shouldn't try impose your way of life on them.
Personally, I'm not sure 'leaving someone to tell you' if they are experiencing problems is the best course of action. Giving options, suggestions and continuing to keep contact, then listening when they want to talk is usually better.