Quite frankly, I would say that if someone runs after other people with a shovel with the obvious intent to hit them, the police will probably arrest the shovel holder first and sort out the story afterwards. And quite rightly so, don't you think? It is quite easy to kill someone with garden tools.I also used to take that attitude - i have been in and out of JHB and South Africa in general a million gazillion times and never had a problem. Last time i was there, i was coming out of McDonalds (yeah yeah i know, but up here we dont have stuff like that so its such a novelty for us when we hit the western world) and 2 young guys followed me. We got around the corner and they pulled a knife on me and tried to stab me. I out ran them - then as running came across a yard with garden tools in the front yard - stupidly, I stopped picked up the shovel and then turned to face my attackers - they then turned and ran - I chased them for 2 blocks (I was annoyed with them and the adrenalin was pumping) when a police car came by - they wanted to arrest me - a white man - for attacking blacks.......sssssh what a mess South Africa is.
Note that I am not disputing that they were the original aggressors. I am just saying that from the police point of view it was perfectly reasonable to stop you and the skin color of the parties had nothing to do with it. Hope you got it sorted out at the end.