At some time between 19.6.3 and 24.4.0, the mod was changed drastically: The Kubrow no longer seems to attack containers. Therefore, the following notes may no longer apply:
When out of combat, Retrieve will make the Chesa Kubrow collect items scattered on the field, such as Pickups and Mods in its mouth, before delivering them to the player. As of Hotfix 18.4.7, all non-mod items will be given to the player instantly upon pickup.
Retrieve will make the Chesa Kubrow attack Storage Containers, breaking them open and allowing it to collect the drops inside. The Chesa Kubrow cannot open lockers, though it will still collect items dropped from opened lockers.
Chesa's new Retrieve functionality can no longer stack with Desecrate and other looting Augments (Pilferdroid/Ore Gaze). This was creating some unintended double dips from a single corpse - the dead can only give so much!