Realms don't starve. Regions do. Regions are the responsibility of the lord.
Yes practically its the lords, yet Dunnera had a Law that says the royal treasurer was "To order the sale of food throughout the realm in order to prevent starvation only."
And also "To work with foreign dignitaries in establishing a food trade, should the realm consume more food than it produces", thusly Davis was autorized and even acted out of duty to order for the food beeing bought.
Again when no food was bought, Davis just complained and eventually the lord apointed a steward.
I don't really see where Davis overstepped to be removed from his position by titans.
As he didn't state anything like if you don't buy the food within this time line then you will be fined or punished or what not.