well according bernuoilli if a fluid moves too fast it creates a subpresure
so according bernuoilli it should be pretty easy to bail out at high speed
the higher the speed the more the vacuum
the easier to jump
edit:
also according the 33 years i have of studies if the plane goes fast enough the subpresure will be so big that the pilot will need oxigen in the empty cockpit
edit:
just to realize how strong this vacuum force and with which force the parashoot is expeeled watch:
a hoollywood movie at which the baddie makes a hole in the plane with a bullet