In chapter 12 of Lord of the Flies, what is the significance of the officer's line, "I should have thought that a pack of British boys... would have been able to put up a better show than that..."

THis is the irony of the whole story. The British were considered the epitome of civilization at the time, mostly by themselves. THese British military school boys quickly devolved into savage little children. The officer is perplexed that this symbol of civility has turned into the spectacle before him.

In the last chapter, the boys are hunting Ralph and meet their savior on the beach. Looking more closely you realize that this man that is bringing them good news is loading them onto a naval ship which is likely to go and hunt it's own enemies. The point of this is to show that the Lord of the Flies (or better said the Id or natural man inside of us) is bound to no abandoned island but lies on all continents, we just "put up a better show than that.."