That's not entirely what I would expect from my XT, but It's not terribly surprising. When starting out, my XT calculates a new route segment from my present position to the point I select from the menu, which your this case would have also been your final destination. Even if the route had taken the entire original path, if the coordinates of "17 Drysdale" were more than few meters off the road, you would have had to go up the driveway to hit the via point and continue.
My routes always Start at a point in the right direction but some distance away from where I expect to get on the bike. Routes from home begin at the saved waypoints "HomeS" or "HomeN", which are at least a few hundred meters up or down the road (but before the first intersections). If I'm touring, they begin outside of the town where I've spent the night. Loop routes from home might actually end at "Home" but more often just stop once I'm back in familiar territory and I find my own way home. So, not really complete loops, but there is no confusion about the sequence when a point appears twice.