The problem with temps and I'm talking from experience of working along side them is most of the don't give a **** about the job. We see a big rise over Christmas of **** up from our mail centre's and that's because over Christmas they get temps in for 3 months work and that's it. They really don't give a crap about what hey do and how they handle stuff as they know in 3 months they wont be in the job anymore anyway. Management in Mail Centres nowadays is strict and they wouldn't get away with stuff like that anymore.
These types of programmes are damaging for more companies than just the one they are secretly filming. Say the programme follows Yodel, other companies like RM, TNT, DHL, UPS will still get some flack and backlash from it as people will assume that is the same across the board in every delivery company.