That's a bolt failure, NOT an ARB bumper failure. Be sure, everyone, that you seperate that out in your mind. Those particular bolts, holding any of the aftermarket bumpers, would have done the same thing. They evidently were either grade 5 bolts, over-torqued, or previously damaged.

This shouldn't be a warning of the ARB, but rather to make sure all the bolts on your rig are torqued properly, and in good shape!!!