Shipping usually involves moving stuff under less than ideal conditions. Trucks rattle and vibrate a lot. The package rattles and vibrates, the electronics will suffer from damage to the case finish. I am sure Pass will send your equipment back with the correct bag if it is serviced. I agree with the idea of no matter what, cover the item with a plastic wrap of some kind Glad Wrap, garbage bags, grocery shopping bags if they are heavier plastic. Flimsy plastic is NOT enough, unless you have plenty of layers.I am certain the company will 'forgive' you for not having the original bag.
On the other hand, not having the original box for heavy expensive items? bad, very bad. In that case I WOULD ask the company to sell you a new box. (Sure it would cost $100, but worth the protection, both for insurance (Insurance usually will ONLY cover if original box!) and for knowing it is way more likely to arrive safe.(and this part is just for general, not d2girls situation.)