Maybe you should. Christians are called to tell people right from wrong. It's part of the message. Repentant sinners tell unrepentant sinners about sin and it's cost.
Hypocrisy comes in if an alcoholic tells others not to drink to excess while loaded. Or a thief telling others not to steal while picking their pocket.
You really don't understand the verse, apparently. When Jesus says, "Let him who is without sin among you be the first to throw a stone at her," he not accusing the Pharisees of adultery.
He was talking about sin in general: there are none of us who are clean. None of us is qualified to condemn another for his sin. The older (and therefore wiser) ones understood His point immediately.
Jesus warned us elsewhere about judging others (see, e.g. Luke 6).
As for the kid who died, sure he was a sinner. He was a sad, confused, and broken sinner. The question is, how should a Christian respond to such a person? What should be our response to his death?
There are quite a few on this thread who have been very quick to prescribe the "proper" punishment for this kid's sin. What qualifies them to cast the first stone? Nothing. They -- we -- have all got logs in our eyes.