To follow it up, the CBP Director of Field Operations in Los Angeles has called the writer personally to apologise, and has identified the agent concerned and are supposedly 'taking appropriate action' to ensure it doesn’t happen again.
James Dyer wrote:"He reiterated that CBP has very strict rules about how agents are supposed to comport themselves and that this kind of bias will not be tolerated. He affirmed that the CBP values its relationship with the media, that this treatment shouldn’t occur and assured me that this won’t happen to me again on my next trip to LA!"
Obviously the average person doesn't get this type of press though, let alone an apology.