Yeah, those reasons don’t seem to add up :/ I read where a mining expert commented that the toxic gases are only an issue in enclosed spaces, not in the wide open air. And the algae doesn’t make sense to me …. what are the chances that both adults, the baby, and the dog all would’ve consumed the affected water? What parent would give their infant water from a river/lake, period? Even if they neglected to pack enough drinking water, I imagine parents would prioritize the bottled water for the baby and only the adults drink the dirty water … And it sounds like they are frequent hikers, so they should be prepared.