Incorrect Speed and Power. Rubberband Meetup

I joined a friend late in a meetup on Sand and Sequoias. He had the Rubberband feature switched on. When I joined he was already moving at around 30kph, the assisted pedal feature actually pulls you past the rider and allows you to get up to speed, but for that first few seconds you are going quicker than the joinable rider. (you see this with the Pace Partners) Once the assisted pedal had finished, it had locked both of us to a speed of 46kph with very little power required. I believe he was also running a WORKOUT. I think what was happening is that the power was being averaged out and consequently being fed into his work out. But this meant we smashed all our PBs for the Tempus Sprint and Titans KOM. This has massive implications throughout Zwift if true.