Make sure you advise AP of this in any investigation.

If parcel had Do Not Safe Drop, and the addressee can demonstrate they were not at home at time of delivery scan (ie. they were at work) if proof is provided to AP then ...  aside from a few feeble attempts to say they no longer provide compensation on regular parcels ... just appeal any decision and restate the case, point out their terms and conditions of sale for the product and you have a better chance of being successful.