Egg move question;

Once Dratini learns Outrage, it can then be used to breed Dratini's that know Outrage from level 1.

The exception I just encountered is as follows; breed male Dratini that knows Outrage, with a female Dratini that knows Extreme Speed. I was hoping the new hatchling would know both moves, but instead only knows Extreme Speed, along with Leer.
What's the deal with that?