It was irregular.

The proper and usual mode of proceeding would have been for the stranger to have stayed on horseback, and for him (the dog) to have barked himself hoarse, till some one came out of the hut and pacified him by throwing billets of wood at him.

No conversation possible till his barking was turned into mourning.

He was not up to the emergency.
He had never seen a man clothed in black from head to foot before.

He probably thought it was the D----.