Grand's plane is a Douglas DC3 on the ground, but a Boeing 247 in the air.
Nick Carter's sidekick Bartholomew enters with a gun drawn, a Colt automatic, but the next cut shows him holding a revolver. This continues until the car chase scene where he regains the automatic.
When Bartholomew rolls out of the taxi he tears his coat at the left elbow. When he appears right after that in the rear of the plane it is no longer ripped.
Nick Carter carries the unconscious Karen Verne upstairs to the bedroom but she lifts her arm to clear the bed as he lays her down.
Bartholomew has sneaked into the storage compartment and stands straight up as the plane taxis and then speeds down the runway and into the air. He doesn't even lean a bit or stagger from the forward force of the plane.