kids in the backseat with booster seats as applicable.
the only time the front airbags would deploy would be when there is a danger of your head whipping forward. side curtain airbags come on when rollover or side impact is detected.
the fact that your car was able to roll forward free means that the energy used to move your car was not transferred to to you, this is good.
if your airbag light in the dash comes on initially during stating the car then goes off then your system is free of errors
the front passenger airbag has a light that shows its status (on/off) up by the sunroof switch.
Have your entire vehicle checked out by a BMW certified body shop as they will be able to check the electric system for any hidden faults.