[Rules] [12.41] Assault Column Modifiers

[Shad]

Although I cannot quote a rule in support of this position, I believe a hex with a contour line running through it is considered to be at the higher of the two elevations present. In this case, the defender in your example would not receive the bonus.

Feel free to slap the map artist who put contour lines through the middle of hexes rather than along their edges!