Former RPR (Registered Professional Reporter) here. I wish that were true! It's usually a matter of the judge you're working for. Most of the time, they look out for you and intervene when they think you're getting behind (because they're speaking over each other, too fast, etc.). You can always stop the proceedings and say something if that happens, but most people do everything possible to avoid that. This particular guy is actually one of the nationally-ranked speed writers, so he isn't going to have that kind of problem often. Some of the attorneys might be considerate enough to go to the extent of trying to be sure things get on the record cleanly, but others will actually try to ding you when you produce a transcript -- "Hey, there's something missing here." I think JW may just be posturing.
It is true that you do not always process the conversation actively, but it's not as though you go into a trance and aren't aware of what's being said. If you're concentrating really hard on staying on top speed-wise, you probably won't remember lots of detail about what was just said at times.
:twocents: