Actually it sounds like he does not know how to properly gauge memory usage.
My Nautilus has a 76M Virtual Memory reserved. However the amount of memory
it is actually using is 25M. Out of that 15M is shared with other Gnome
applications. It uses about 4MB of X memory.
So Resident Memory - Shared Memory + X Memory = Actual Memory usage required
to run Nautilus. Which is just about 14 - 15 MB. That is how much I would
save if I killed Nautilus off.