Slashing is always used in proof of stake. You get slashed, not if you break the rules, but if 51% of the stake decides to slash you. It can involve that 51% getting your stake, but it could also mean it just goes away
A justice transaction is enforced with clearly defined rules using pre-decided funds (the fidelity bond) as justice for your money being attempted to be stolen by the other person.
I hope you can see why I don't want the terms mixed up