His experience doesn't seem all that bad. It looks like they were merely doing their jobs trying to ascertain that they aren't making a mistake letting him in. If the immigration officer isn't sure of something (either because of an unclear answer to a question or a nervous vibe), it's not abnormal for him/her to ask for a more thorough check of the person. I wouldn't expect them to clear everyone with a quick, cursory glance of a passport or a green card.

I sympathize with him, but it doesn't look like his rights were violated in anyway.