Odd, I have never heard of an SEI manufactured Vortex bending a tine with normal use, nor 'blooming'. SEI has sold and given countless examples in various sizes from .50BMG down to 9mm to every branch of the US armed forces and are widely used to this day. This is a recent example:
http://www.smithenterprise.com/spec/sei-50cal_rel01.pdf
I would venture to say, the tine of a blackout is longer than on a vortex. The blackout is not much more than an extension of the old Colt three prong flash hiders - 2nd model - from the early sixties. Which by the way were superior to both the A1 and A2 models in efficacy.
I don't doubt that the Vortex is probably one of if not the most counterfeited designs, so that may be the root cause the problems noted in his statement. Hell, even the Army stole the design, got sued by SEI, and lost.