Some of these clearly anarchistic comments are very disturbing.
I find it odd that folks who don't like authority at all are so ready to eat up this clearly one sided story feed to them by the media. No where in any story written about this has there been a CBP comment. Just the traveler's statement. I would bet there is a whole lot more to this story that has been reported.

The reason a CBP Officer asks you to turn off your car is so you don't back over him while he is checking your trunk.

That being said, saying please does goes along way.