New timber floorboards - cracked board

Hi,
After some advice.
We have just completed our new home, and have moved in 1 month ago.

We have Spotted Gum hardwood timber floorboards throughout.
Just noticed that one of the boards has cracked. Not separated from the adjacent board, but has a split running through and along the timber grain. (not the result of misuse, dropping objects or anything similar)

Question:
How should the builder repair this?
Replace the whole board (which may mean replacing a whole section/room)?
Sand, Putty and re-vanish the "area" that is damaged?
Other?

thanks in advance,