The delivery guy has a slider to accept, pickup and complete the order. It should be a rare case where this happens. It's understandable that if it's a button, it could be clicked by mistake.
As of now there is no option on Admin to change the status like this.
But order status switching Accepted by Delivery and Picked up by delivery is quite safe. So if you want to do that, you can goto PhpMyAdmin and change the
orderstatus_id of the order from