So the case he talks about has set the precedent in law for carry a multitool, nothing we can do about that just that everyone needs to be aware. When you read up on the case the guy had the knife out and had chased two people down the street and threatened to stab them...no mention of that in the video!
For everyone on here I think the question has to be what were you doing to get noticed by the Police in the first place? If it's on your belt under clothing or in your bag no ones going to know, if it's on show to everyone then expect to be pinned to the ground by an armed response unit and arrested. I'm sure many of us have nipped out for a break and without a second thought still had screwdrivers, podgers and blades on a belt but there are mitigating circumstances that you have been using them for your job. You just need to make this very clear in your initial interview and you might get away with a fine instead of going to Court. If you do get stopped for any reason while carrying then keep your hands away from your body and visable, talk to the officers telling them exactly what you have and use slow movements.
A sign on the exit doors 'Are your tools safe' might be a useful reminder (but not an excuse to lock the apprentice in a flightcase!)