I don't think this should count as an easter egg, it's just what happens when you don't do anything to help the Pillar of Autumn escape
Games have had things that happen when you do something wrong like some of the Spiderman games i believe
if you dont help destroy the cruser THAT CRASHED at the start of the skip the screen just gos white and you hear your guy die
to evem see that happen you have to:
beat the hole mission on the hardest difulcty to that point
get on the gun shoot random stuff
hit a series of invisable switches
them finly kill the cruser if you watch the hole thing