Uncle M, I have been in an emergency descent when I was a copilot on a B737 with a cracked windshield. The captain started an emergency descent between SFO and LAX from FL330 to FL240 but had initiated it before I got my mask on. He tried to talk to me through the interphone but when he pulled his oxygen mask down he pulled out the mike jack. The communicate part was done by taking my mask off to tell him what I was doing getting the descent clearance and shutting off the windshield heat that was arcing and adjusting standby pressurisation. It was an outer pane so the checklist said no restrictions, maintain 250 knots max below 10,000 ft. I guaranty you no pilot is going to maintain level flight in an explosive depressurisation if communications can't be established. The FAA likes to make everything just like you would do in a simulator.