I think it's worth remembering that this was a storage procedure that was also already abnormal/odd because of the specifics of the existing shielding. I think it's somewhat understandable for a technician to trust that the chemists know what they're doing in that kind of circumstance. If they had concerns, they may have even voiced them, but as is often the case, if the authority confirms that even though it's strange it's correct, it's not surprising that a technician would follow the directive. Even the authority figure may have verbally confirmed, "you said an organic absorbent??" "Yes, that's right, inorganic absorbent." Maybe even in a meeting that was meant to clarify written procedures.