On getting tricky . . .
I've been a beekeeper in Montana and Oregon since retiring from teaching. The following thumbnails of data may give you some ideas for your story.
Polenth is correct that European honeybees in the wild are usually quite peaceful. To arrange for your honey thief's goats the greatest chance of being stung, they should be dark-haired and shaggy.
Most beekeepers wear white or light colors because natural honey robbers are bears and natural bee-eaters are skunks -- both dark haired. Attacking workers become entangled in hair and after stinging, the mortally wounded bees secrete a pheromone to attract and enrage more workers.
PDR is also correct that the goats must be close to the hive -- perhaps tethered or otherwise prevented from fleeing. The more agitated the goats (perhaps blundering into the hollow log where the wild hive is housed) the more mercilessly the animals will be attacked.
I can tell you from experience, honeybees from African strains (bred to produce more honey) are the most aggressive, so your wild hive could be "Africanized." I worked with such bees from Texas and points south, and they attacked a black horse and rider in dark clothing merely crossing the flyway between a blossoming alfalfa field and the hives.
A technical point: Although most readers consider a swarm is any group of bees on the move, a "swarm" is an action where a large hive splits, and a queen leads a number of workers to a new location. At that time they have gorged themselves with honey and are the most docile.
To be in their best in delivering their worst (and to have a surplus of honey available to steal), the hive should be established a while after its swarm to a new hollow log.