When you go to collect your tools ask the officers to explain why the tools were seized to avoid these issues happening again. If you don't get any response, a well written letter or email might help, again to avoid this happening on future trips.
Clearly I, nor anybody else here witnessed either the campsite incident or the station incident so it's really hard to give any advice. I'm not doubting your account, but it is from your view only.
I am a serving police officer, and have had friends describe a traffic stop in which they were singled out, insulted, mistreated etc and then later spoken to the officers concerned who stated they were insulted, mistreated etc. There really are two sides to every story.
I have been issued a leatherman tool which I carried on search duties. Officers use them for cutting seatbelts, cutting plastic cuffs, plastic bag seals, the list goes on.
Cutting down hanging bodies? Sure. If there is a chance of recovery you are duty bound to try and preserve life. Even if the person is dead once the photos are done the body stills needs to be cut down.
Please try to remain positive, it is our responsability as bushcrafters to prove we can use our tools responsably and demonstrate to the public that knives aren't always something to be scared of.