from the screenshot i can see you have turrets. Some of them deal damage also to the environment when they attack/defend. If your sure they did not attack critters arround your BA you should send in a report (try find the cause for reproducabilty), but i'm quite sure the reason is given by your turrets or incoming enemys

Possibly, i never tested something like that. You can test it, either kite some critters in range or spawn them inside the range of your turrets