Forgot to Forget

In OTL, at 28. June 1914, Archduke Franz Ferdinand d'Este went to Sarajevo. Organization called Black Hand prepared assassination, but the first six assassins failed. Seventh assassin, Serbian student Gavrilo Princip, thought the assassination was cancelled. Archduke Franz Ferdinand wanted to go to hospital, visit the victims of attempted assatination of Nedeljko Čabrinović. They didn't want to go through center of city, but they forgot to tell the driver. So they went around the place, where Princip was having snack. He shot the Archduke and his wife, and actualy caused the First World War.

But what if they told driver they changed the way?