DON'T OPEN THE EGG CASE!
Turn off the lights and shine a flashlight at the egg case. This will promote some type of mocement from the embryo. You should be able to see it attempt to manuever away from the light. At the very least you should be able to see some type of gill function.
I have a bad feeling the "white stuff" that came out was part of the yolk and the embryo died. Hope not though.
Why in the world were you squeezing the egg in the first place? Left on it's own, the shark would develop and eventually hatch.
Also, you do not need to help the shark out of the egg. They can do that on their own just fine.