For all of you insisting the OP should name the dive op, the point of this post was not to tell everyone "don't use this dive op!"
The point of the post was to tell you that this happened with a well-established dive op... so you should assume it could happen to any dive op. I'll admit that when I dive in Coz, I usually bring my SMB, whistle, and dive-alert airhorn. But sometimes I slack off, and trust that everything will be fine... as it always has been.
The point of the post is to remind everyone to be vigilant and be prepared to handle these kind of situations. It could happen with any dive op.