Am I suprised?
Am I surprised? NO. This is an endemic problem and has been since I joined this industry back in the mid 60s. Hence the names given to "Gatnick" & "Thiethrow". As airport expansion gathered pace with more and more under cover baggage handling areas growing, lack of surveillance cover.
One member sighting another stealing is either coercerd and/or threatened in to joining or ignoring the practice.
The only way to stop this, is heavy penalties, and much better screening, and surveillance of staff.
It is a management failing for the lack of oversight and control.