How does Robert regain his sense of pride after Jack uses him for a pig hunt?

Robert makes a joke out of the event in order to regain a sense of pride.

Jack's arm came down; the heaving circle cheered and made pig-dying noises. Then they lay quiet, panting, listening to Robert's frightened snivels. He wiped his face with a dirty arm, and made an effort to retrieve his status.

"Oh, my bum!" He rubbed his rump ruefully.

Jack rolled over.

"That was a good game."