The reason why Ongaro has been accused of using a gyro is simple.
Back in Italy they have races like Padova's various one of championships where Gyros and additives have been fully allowed.
Ongaro and other Italians have been seen to be using , hence he has always been known to have used one.
I have tested Gyros and they are not easy to set up and use, But i can tell you Ongaro is super super talented, I think they needed the big tech check after to fully put to bed any rumours of cheating at the worlds and to give him the credit he deserves.