Whoever wrote this article should teach journalism classes. The details are precise and to the point.
Chain mail suits do a good job of spreading out the force of bites and such but they are not particularly good at resisting penetration.
Last year we were watching a shark special and a diver had on one of thse suits. Her hand was bitten and fingers nearly taken off but it wasn't as bad as it could have been. Anyway, the "glove" was crushed into her hand, breaking where the shark had bitten. I don't see how it could protect from a stingray barb.
http://www.jerrylabella.com/stingray.html
Never underestimate the penetrating ability of a stingray’s barb, even on the smallest of stingrays. The stingray’s barb is designed to penetrate virtually all sorts of dense materials, including wood and leather. And as unbelievable as it may seem, it’s been documented that large stingrays are able to drive a barb through a boat’s wooden planks or completely through a persons arm or leg.
As I understand it, the question of what is the diameter of the rings versus the diameter of the barb. If the barb is larger than the rings it will be stopped unless it exerts enough force to break the ring. Most likely the barb will penetrate until the taper of the barb is larger than the rings. This would possibly still allow several inches of barb to penetrate.