CB Range discussion

I’ve been playing around with plastic locks recently and have come away a bit let down. The idea behind the plastic lock is to ‘break glass in case of an emergency’, without totally ruining the cock cage. The Key Holder will know if you cut it off because there’s a number on the lock. However, I’ve discovered that once locked with the plastic lock, giving a small tug on the latched end part allows me to pull it out from its hole while keeping everything else intact. Then you can just pop the end piece back in without raising suspicion. Did I get a batch of defective plastic locks or is this common? I thought they were more secure.