There are more of a cousin of the Bushbuck here, Waterbuck. I know those can get aggressive, know one that is on a friends wall, it put its horns into the ranchers truck door one day after it had killed other animals. The rancher said he barely got in the truck in time.
Seems another species of animal was in heat and had that one worked up / frustrated looking for something.
Waterbuck aren't really a cousin of Waterbuck.
Bushbuck belong in the spiral horn family along with elands, kudus, etc.
Waterbuck are in a family consisting of puku, kobs, and lechwes.
But yes, I do believe of their aggression. The ranch where I hunted mine down near Crystal City has a herd of 50-60 and the bulls during the rut would go wild and start killing each other.