No no no
A scattering blast may hit targets out of
LOS, you may however NOT target a unit outside
LOS unless it also has the Barrage rule.
A scattering Blast may also hit and resolve damage against a second unit outside
LOS that was not initially targeted.
If you can see part of the unit you must first resolve hits according to the normal wound allocation, however: if the unit targeted has models outside of
LOS that are hit by a blast these are resolved last. first you resolve all direct fire hits. if there are models left in
LOS then the hits from the blast [that scattered and hit models outside
LOS] are resolved against the models in
LOS as per the normal wound allocation rules. If there are no models left in
LOS then the hits from the blast [that scattered and hit models outside
LOS] are resolved against the models outside
LOS per the normal wound allocation rules. [Disregarding the fact that they are outside
LOS]