It is still very hypothetical since we have no idea what happened, but official statements try to stick to actual evidence, and with an older person confusing the pedals, there is no real physical evidence of what happened. So they can only say that it did not appear to be intentional because it was not intentional, and the only person that truly knows was the driver, who might not be fully aware of what they were doing at the time (or the shock of it, and humans incredibly fallible memory make true recollection impossible).