Sounds as if Villa's canard lacked sufficient vertical tail area. Conventional, tractor configuration aircraft tend to Dutch roll if they are a bit shy of vertical tail area. Canards usually need far larger vertical tails to counteract the yaw-destabilizing effect of the fuselage area ahead of the CG. Their vertical tails are also normally much closer to the center of lateral pressure, reducing their effective moment arm. I found winglets or tip plates on the tips of the main wing of canards to be very helpful, particularly if the main wing has some sweepback. They can add badly needed lateral area, while reducing induced drag, thus partially offsetting the additional drag that they cause.