User blog comment:RobinCarr/Virtual Dino Den, Explore How Baby Dinos are Born in the Dino Den/@comment-5326188-20120822003404/@comment-4960207-20120823200500

I think the HH hatch has nothing to do with the fusion success or failure. It's once the time is done (either on it's own or through HH) that is then goes to the server to find out if it was a success or failure.