He says this is also a world record, but JET got 0.67 in 1997 (according to Wikipedia). The missing asterisk may be that this Q was the average for the whole shot, whereas the 1997 result may have been measured over a short time. Just my speculation, based on slide 21 here: https://fire.pppl.gov/iea_bp_w60_stork.pdf
Edit: Confirmed by this comment https://www.reddit.com/r/fusion/comments/soc5xo/oxfords_jet_...