they way I am reading it, some items may arrive broken although their packaging appears to be intact upon receiving inspection(packaging shows no damage or tampering - integro and illeso)

A bolla I am interpreting as being a transit company bill of lading.
Riserva can be reserve, set aside, segregate, put aside (as damaged material would be if it fails the receiving department inspection )

Since when the freight is in transit the actual carrier (the company transporting the material) is liable for any damage, under normal circumstances a claim can be filed against the freight company that transported it (or consignment of the freight can be refused on the basis that it is damaged)

The best thing I can come up with is that:
the vendor agrees to replace any products that, when unpackaged, result to be damaged and for which a claim against the Carrier (freight Company) may not be filed (the packaging appeared to be intact and untampered with).