He could not imagine any one's stopping Bull from going into a fight if he wanted to go into it.
And perhaps unconsciously Whitey's under lip and jaw shot out, and his face took on much the expression of Bull's.

Whitey would like to see any one stop _him_ from going.
That new, elderly cook not only approved of Whitey's purpose of disobedience or rebellion, he aided him in it; yes, if it cost him his job! There was the iron-gray colt, still restless and as ready for the fourteen-mile ride back as he was for his breakfast.

While Whitey limped into the ranch house for some clothing and footwear, the cook had his own troubles getting his own saddle and bridle on that pony.
When Whitey reappeared and was helped into the saddle, he let out a yell of agony and helped himself out again.

This would never do.

The leather felt like hot iron.