I saw the sentence here: https://www.youtube.com/watch?v=sqkQMVIoUeg
And the sentence comes at around 10:00
They found that people claiming 75-plus-hour work weeks were off by about 25 hours.
As far as I know, "off" can mean "away from a place" or "away from work". But does it mean "people claiming 75-plus-hour work weeks" actually only "work 50 hours per week"?
I would like to know if anyone could help me understand the sentence (and why audience in that video laugh).