Not having a gun, imho, means little with regards to whether or not they intend to cause harm. They may not have had access to a gun, for one. Knife crime is significantly worse than gun crime in many places, especially the UK. People can get hold of guns pretty easily here, if they have money and know who to ask, and yet knife crime is the preferred method in a lot of cases.
I've searched many people and found things like lock-knives, butterfly-knives, plastic knives which are undetectable and thus highly illegal, and they're all things which you have to assume are intended to cause harm. You simply cannot make the conclusion that they were merely intended to scare an individual.
Just recall what those disaffected youths did with knives and boxcutters on a certain September 11.