Could be I'm misremembering the details, but I swear on the BBC they interviewed people that lived next door to the explosion as well as an official of the Anglican hospital (who to be fair was outside of Gaza). Neither called into the question the facts - but were not first hand witnesses either

If everyone (ie all new agencies) screw it up then it's a systemic problem. Just blaming the New York Times or whoever is myopic. You fundamentally need some different model of "slow journalism". Probably something more like Wiki where people need to site sources and things are updated and edited as they come together