What about a sound recorder? You could use it in that first design meeting, and then have something like dragon dictate convert it into text. If the meeting was fruitless, meh, it's not really all that hard to do the conversion (it's practically free, compared to having an actual transcriber). However, if it turns out to be important, you have a transcript, and if necessary, can go back to the original recording.

Yeah, it doesn't work perfectly, and you don't want to be wired all the time, but if you're in a meeting that you know decisions should be made in, you could prep for that meeting with your recorder. So, when questioning that decision comes up, you have your artifact.