In video game Dragon Age Origins one of the characters says "But now I've sidetracked us. Let's move on."?

In video game Dragon Age Origins one of the characters says "But now I've sidetracked us. Let's move on."? Should he or should he not have said that considering that game setting is something close to medieval age? Does the verb "sidetrack" originate from railroads? (I don't know, cause English is not my native language)