Just be happy your parents are safe! If they have nothing then the car did its job very well, even if the Airbags didn't deploy!

Concerning this question of Airbags, if you're really concerned you should hire an expert to analyze the crash (surely your insurance will do so anyway) and see if the Airbags had to pop.

Looks like a big crash, but if it's not really frontal but side-frontal (hit in the front corner) then the Airbag won't deploy.






And if the cow absorbed a lot of energy by beeing blasted away, maybe the deceleration of the car was not hard enough to make the airbags deploy.