Dr. Davila has a mole under her right eye. This mole disappears and reappears at different times.
The helicopters used in the series nearly always lack a tail rotor. Without a tail rotor or a counter rotor, the torque generated by the spin of a rotor blade will cause a helicopter to spin out of control.
Ryu's name is consistently mispronounced as 'Rye-u' instead of its correct pronunciation.