Temporary annotations of the magic wand tool are cancelled by moving the cursor to the starting position and releasing the mouse button. In some cases this may become tricky because the annotation should be created but the mouse is not yet far enough away from the starting position. Maybe implement a shortcut (like shift) that can be pressed while the temporary annotation is drawn? As long as the shift key is pressed, the temporary annotation cannot be cancelled no matter how close the cursor is to the starting position.
Temporary annotations of the magic wand tool are cancelled by moving the cursor to the starting position and releasing the mouse button. In some cases this may become tricky because the annotation should be created but the mouse is not yet far enough away from the starting position. Maybe implement a shortcut (like shift) that can be pressed while the temporary annotation is drawn? As long as the shift key is pressed, the temporary annotation cannot be cancelled no matter how close the cursor is to the starting position.