pgr_nodeNetwork does not cut intersections on intersecting points.
Consider the following simple case of two segments crossing on (5,5) :

create table network (id int, the_geom geometry(linestring) );
insert into network values (1, 'linestring(0 0, 10 10)'::geometry);
insert into network values (2, 'linestring(2 0, 8 10)'::geometry);
select pgr_nodeNetwork('network', 0.001);

The "network_noded" table then contains 4 geometries :
LINESTRING(0 0,1 1) <-- the first segment split on what seems to be the
projection of the starting point of the second segment (?)
LINESTRING(1 1,9 9) <-- split on the projection of the ending point of
the second segment
LINESTRING(9 9,10 10)
LINESTRING(2 0,8 10) <-- the original second segment

It should split the two geometries on (5,5)