Yeah, it happens and it always sucks. It probably happens a lot more then people realize, but a lot of people won't admit to it and post pictures as proof. I thank you for doing so because I think that people who want to get into breeding really deserve to know that it's not always going to turn out to be cute little baby snakes all the time.
In the 20 years I've been breeding snakes I've had several babies that look like that. Granted, percentage wise, it doesn't happen that often. I'd estimate that it's less then 1% of the time. But on the other hand I wouldn't say it'll never happen and people have to be aware of the possibility .
I'm sorry it happened to you on your first clutch, but congratulations on the other 9 hatchlings. The healthy ones are what make it all worth while.