I would additionally add that, while he spent a while talking about one of the positive outcomes for a while at the end, even the tone of that section really points out the utter luck that was involved in a lot of the successes.

It was a horrific day, but a pivotal one for at least the next 40 or so years of history. Had the Allied forces not been able to break into Normandy the outcome of the war was no certain thing, even with the success in Italy.