Good guys Bill and Davis are apparently clubbed unconscious by an unseen hand while exploring the Mystery Squadron's secret cave. Initially Davis lies to the right of Bill, but later he's seen laying on the left.
Chapter seven: Various shots of Cromwell flying a Mystery Plane dressed in Mystery Squadron flying togs, then in his own flying togs.
When Mystery Squadron bad guy Roberts is shot dead while shooting a flame-thrower from his plane, he falls halfway out of the cockpit and hangs there motionless. Despite the fact that apparently no one is piloting the craft, it manages to make a perfect three-point landing and come to a halt all by itself.
We all know how Collins got his wound, but no explanation on how Dr. Flint got his.