Chester, not to start an argument, but I'm assuming "prevailed" means settled. And trust me, I love to see them pay. But the likely decided it would be less expensive to settle than to fight.
It is not a violation alone for them to leave a message that it is an attempt to collect a debt. The violation spelled out in the FDCPA is that they cannot reveal the information to a third party. The message has a potential of third party disclosure, but is not a violation until 3rd party disclosure occurs. If have read case law on the issue when I was researching my claim. I will see if I can locate it.
The envelope example you give is different, because it is spelled out what markings are a violation, so no other event needs to occur if they use these markings.