He must have been displeased when they were conceived, since He knew what was going to happen...
Maybe I'm being obtuse, but I don't understand the concept you are trying to convey.
I'll take a stab at it anyway...
The twins, and doctors have free will. The Lord did know what was going to happen, but the twins and doctors could have chosen a different path, in this alternative path, they are now still alive?
Help me out here, so I understand your post.
5.56mm
I have a problem with free will. Since God knows before hand what each of us is going to do and He cannot be wrong, people must do what He knows they will do. How can people do something other than that which God knows they will do?