GSF...I live in the lightning capitol of the world, and though I would never go IN to my hives with an approaching storm, it never seems to agitate them if I am near by. Are you sure you didn't walk in too close during an orientation flight? Orienting bees sure aren't the best flying Aces...so perhaps you being in their way created the agitation problem? A few bees just trying their wings for the first time, can easily get caught up on a shirt, hair, whatever, and then if brushed/balled away would put alarm phermone into the air, and would result in a more defensive reaction from elder guards in the hive when you came back in for more lookie-loos. Those were my thoughts when reading your post! Check the hive the same time tomorrow...I can set my watch by orientation flights of my hives. Robbing is UGLY! Kind of like confusing orientation flights with swarming....Once you see a swarm, you never have a question of it again!! Good luck!