this was V's doing by the way,
look at maybe_hack_cruiser_chase_abort()
for those of you unable to look at the source at the moment it goes a little something like this
int maybe_hack_cruiser_chase_abort()
{
	ship			*shipp = &Ships[Pl_objp->instance];	
	ship			*eshipp = &Ships[En_objp->instance];
	ai_info		*aip = &Ai_info[shipp->ai_index];
	// mission sm3-08, sathanos chasing collosus
	if ( stricmp(Mission_filename, "sm3-08.fs2") == 0 ) {
		if (( stricmp(eshipp->ship_name, "colossus") == 0 ) || ( stricmp(shipp->ship_name, "colossus") == 0 )) {
			// Changed so all big ships attacking the Colossus will not do the chase code.
			// Did this so Beast wouldn't swerve away from Colossus. -- MK, 9/14/99
			//if ( stricmp(shipp->ship_name, "Sathanas") == 0 ) {
				// do cool hack stuff here
				ai_clear_ship_goals( aip );
				aip->mode = AIM_NONE;
				return 1;
			//}
		}
	}
	return 0;
}
basicly it says that if the mission file name is sm3-08.fs2 (my eyes bleed already) and ether our ship or the ship we are atacking's name is colossus, don't do anything.
sm3-08.fs2 == 'their finest hour'