I would fly it again and try using the rudder during normal flight. As far as I can tell, from my experience and reports in this and other threads, rudder input causes the GP Skybolt to roll in the same direction as the input. I wonder if you didn't just catch a gust under your wing, because that's not the way the plane usually reacts to rudder input.

In fact, using rudder to make coordinated turns has a tendency to roll the plane causing the need for opposite aileron. This is the reason that people who have actually flown the GP Skybolt often mix in opposite aileron to the rudder. Rudder is master, aileron is slave. I forget the percent on my Futaba 7c, maybe -15% or so. This will let you use rudder in coordinated turns and help a lot with knife edge flight.