That's one part of several strategy points to this level. To get 19.xx you must hit far right wall at 12.xx. If top and bottom are done perfectly in the same run, 19.2x-19.4x is possible!
btw...just wanted to add that although faster times are possible, Oliver, Tabs, and DK have awesome runs as it is. It would take an insane person to get a 19.4 or better on this level......here here to insanity!