From a dramaturgs point of view, its actually better not knowing exactly how Barker escaped. We get all kinds of hints -- he was sent to Australia for life. Anthony finds him half dead (presumably in the water, since his ship rescues him). So clearly Barker has gone to extraordinary, perhaps violent, lengths just to return to London. Without those high stakes, it would be less "believable" that he would become a merciless killer simply upon discovering that Lucy has been poisoned.
Sondheim and Wheeler do a find job of making Sweeney Todd a realistic character, despite the over the top proceedings of his revenge. Knowing that Barker had say killed 4 guards and jumped two ships to get to the UK, would push the story over the top.
Updated On: 10/8/05 at 11:25 PM