It must have been an equipment test flight of some kind(?)... I don't think it's common for that kind of training to be done with the actual plane. I could be wrong, but it seems crazy, given the operating cost of such a plane vs. two hours in an adequate simulator.
Of course,
somebody's got to fly it for such a test, so it's a good opportunity for some practice for somebody...

Flying the rectangular pattern, however, is not that unusual- sometimes it just works best for traffic sequencing or to avoid bad weather near the airport. I've been on a few scheduled flights in heavies that ended with at least two legs of the "GA" pattern. And often if a heavy has to return immediately due to a problem discovered on takeoff, they may very well stay "in the pattern".