Wouldn't argue with any of that.
Thanks, I was hoping my advice would be heard, this is a topic I am pretty up there in experience and knowledge.
I agree it's a sad time. At least you realize what you need to do in the future and that's a big plus. Many would have blamed the lady and the carrier (like they have above)...it's possible to that the dog was a 'bad dog'. This happens.
There was a large rotty that we'd board for the owner. He was a well-known dog trainer. His dog was apeshit crazy. He finally got it tolerating his family, but we couldn't even walk the thing. He was locked in a kennel run and we had to just throw the food over the top. Even trying to slide it in at the bottom was dangerous.
One day someone took his lock off the gate and he was able to knock it open. I was pinned on the top of the cages for over half an hour.
A few months later the dog turned on his wife and daughter, both were severely mauled and lost limbs/use of limbs. It was then he finally decided to end that dog's life. His wife divorced him and won total custody of the daughter.
A dog is a great thing to have. I'd get a more manageable and 'easier' breed next. Keep in mind the 'smartest' dogs are the hardest dogs. Any dog is smart enough to learn all the basic commands and be content with an average home life.
Golden Retrievers are probably my most recommended dog. Their big downfall is shedding. Golden/Black Labs are good second choices (I am assuming you don't want a small dog due to having a Great Dane).
I'd go to the pound over a few months and 'test drive' some dogs. They are usually looking for someone to hang out with, even if you don't take them home.