I didn't think the crews were blamed for the German deaths, and deaths of POWs, were they? Well, I suppose some Germans did, but the criticism in the UK was presumably directed at various politicians and military, as with Dresden. In fact, the Geneva Conventions eventually outlawed attacks on dams, with some exception (if they are being used for military purposes).
The Germans threatened to flood much of Holland at the end of the war, but I think, if my poor old memory still works, that that was considered then to be a war crime. Anyway, they flooded some areas, but not all of them.
