Well, that's not a huge beer...but sometimes fermentation is a little bit aggressive. Probably due to the added sugars from the blueberries, but maybe you had a fresh batch of yeast, too.
For what it's worth, I use a blowoff tube all the time, every time. If I go bigger than 1.080, I use a 1" blowoff tube. After your first blown bucket and the clean up that ensues, you'll find a lot of value in a buck's worth of hose.