The fact that the BD half dome cracks under flexion and is a lightweight, non-durable helmet shouldn't be any surprise to you. I've seen that fact mentioned in every review I've ever read about the helmet. It's also immediately obvious when handling the helmet. Caveat Emptor? How about a little personal responsibility?
You got your money back for returning a heavily used helmet. I don't think you should be complaining (except maybe to BD for making a flimsy helmet in the first place).
True, the REI staff is not as knowledgable as folks at FF or PMS. So what? It's a good place to buy stuff becuase they have just about everything and their return policy, as you demonstrated here, is awesome.
In short, CLIMB YOUR SIXTY METERS AND SHUT THE FUCK UP!
Nice climbing on three fingers by the way.