Essentially he is frustrated and releases his frustration by careless and violent action.
"He desires only to do good in this world, and so often, I don't comprehend how my careless actions might imperil his work."
His careless action brought a Comanche attack in which he was seriously wounded.
It seems to me that by a careless or willful action, I could break the circle, and well, what?
Two little things had happened that day, and the influence of a few words, a careless action, was still working in the active minds of the girls.
Darkhorse had no fear for himself, but he knew that careless action might very well rob him of his only possible chance to find and stop Shade.
They may have betrayed themselves by some careless action.
It was as though a poet had brought me his work to criticise and through some careless action I had destroyed it.
There must be no careless action regarding a new 'European Gold Coast'.
However, the authorities discovered them due to their foolishness and careless action, causing Alexander's servants to be killed.