Rear Bumper shocks, not suspension. After a rear end collision, need to replace?

What is your question?

Had a rear end collision in 2002 New Beetle. The shocks in the rear bumper did deploy, contracted to absorb the hit, then returned to original position. Have seen that the bumper shocks must be replaced after collision. They are only good for one incident. Insurance Adjustor does not seem to know this. Any comments? Ideas?