If you notice a parent is having a car seat safety issue, should you ALWAYS say something?

One of my husbands friends recently posted on Snapchat his 9 month old out of his car seat while the vehicle was moving. He was standing up in his car seat being tossed around. He apparently thought it was a joke and was funny because he was “driving slow” this personally pissed me off and really questioned his parenting skills. (I did give him some choice words)

So should something always be said when it comes to car seat safety or would you stay quiet if you saw something potentially dangerous?