Blocked Fire and elevation, 4th Ed.

[Blackcloud6]

10.1 says this in regards to blocked fire and friendly units on different elevations: "This rule applies to units firing from a higher elevation through their own troops on a lower elevation as well."  What about the converse?  Say there are units at the base elevation, firing at units at level 40 with a friendly unit in between on the 30 level with no open hex between the friendly unit on level 20 and the target.  Is the fire blocked or not?  I think that since the statement in the rules specifies higher to lower fire that lower to higher is OK.  So I think the fire in my example is OK and not blocked.  What do you think?