I'm afraid it may not be very easy to repeat, as the file I'm using
is a .cine file of around 16G! I know this sounds an extreme case, but
some professional movie cameras shoot raw...

I didn't use any special switches, just something of the form of

dcraw_emu -s 700 mytestfile.cine

I'm afraid that I'm going to be very busy for the next couple of days, but
a good experiment I might perform would be to create a file with very small frames, so I
can find out if the frame count or the file size is the issue. That might
also create a test case that can be loaded via the Internet.

Mike