Yeah the glass completely shattered. One time it happened to me in the middle of the night, I heard an explosion, woke up and ventured downstairs to see my conditioning area completely covered in beer, smelling like beer, and glass everywhere. The 2nd time I had it conditioning on my top step to my basement, after checking the temps a few times with my head right in front of the growler, I went to check on them one day and the same thing. Glass everywhere down the stairs, all over my other carboard boxes of conditioning bottles, and beer everywhere.
They have growlers that are made for conditioning, but they are not the norm, and you have to specifically seek them.
I'd suggest buying a 2.5 gallon keg or maybe a 12 pack of 24oz bottles if you want to bring to a party. Growlers are scary :|