"Good'n on us, Casey! Darn' good joke on us--'n' on the burro!" Whereupon they drank to Casey solemnly, and one and all, they proclaimed that it was a VERY good joke on the burro.

A merciful joke, certainly; as you would agree had you seen the poor brute hungry and hobbling painfully, hunting scraps of food amongst the litter of tin cans.
After that, Casey wanted to sleep.

He forced admissions from the three that he, Casey Ryan, was all right and that he knew exactly what he was doing and kept a level head.

He crawled laboriously into his bunk, shoes, hat and all; and, convinced that he had defended his honor and preserved the Casey Ryan reputation untarnished, he blissfully skipped the next eighteen hours..