We call a standard work day 8 even though it isn't exactly 8. If indeed the idea was to shift a standard work day from approximately 8 hours to approximately 6 hours, it seems reasonable to refer to it as the "6-hour work day". (I haven't read the report, so won't comment on whether that was indeed the focus, as opposed to a more flexible 30-hour week.)
Everywhere i've worked that has actually cared about hours meant 8 when they said 8. My current job (as stupid as I think it is) requires me to be at work and not on lunch for 8 hours a day.
The person you are calling inaccurate said as much in different words.
If it wasn't exactly 6 then you shouldn't call it 6.