[Rules] Fall of France Sunken Railrods

[Bangla]

Hi
A quickie.  The special rules for Fall of France state the following:

• Spotting:  Units in non-sunken-railroad hexes can spot units in sunken railroad hexes to which they are adjacent.  Units in sunken railroad hexes can spot units in all other hexes normally.
  

Does this mean that, similar to Limiting Terrain, the unit in a sunken railroad hex can be spotted from afar if it fires, or does this special spotting rule overrule that and they can 'fire at will' and still only be spotted from an adjacent hex.  We are assuming it's the former, but just wanted to make sure before we start play on Friday.

Cheers
Bangla