ommis, it is not just semantics that you are arguing. complete emunah is believing that whatever happens, happened by the hand of Hashem”
Your understanding of what Yad Hashem means, and mine, may be different. Perhaps Leiby would have died by some other means had he not encountered Levi Aron. But the fact is he DID encounter him, and that encounter is what caused his death. Clearly Hashem made that decree for Leiby to die that day by the hand of that man in that way. Does it make ANY of us feel better to know that?
I think we should focus on ways to prevent this type of horror from occurring to another child chalilah. I am not arguing with anyone here. I just see this from a different perspective, one in which we learn from this tragedy how to be better people, and how to better protect our precious children.