The question was whether being polite or brusque (and he wasn't rude after all, just perfunctory and not actively polite) in refusing to answer CBP officers' questions would have made much of a difference to the CBP response.
For that matter: Most people cannot up and quit their jobs. Having a job is not strong evidence that someone wholeheartedly supports and believes in all policies and practices of their place of employment. In many cases, it is only evidence that they prefer putting up with the crap at work to putting up with the alternatives (such as homelessness). Even in cases where someone does strongly disagree with what goes on at work, most people cannot afford to simply up and quit and there may be little they can do to change it while they are there. If they really feel strongly about it, they typically begin job hunting and leave as soon as is practicable without cutting their own throats. Additionally, if they have any sense, afterwards they tend to keep their mouths shut about the things they did not approve of. Talking trash about a former employer can be a good way to ensure that other people will be reluctant to hire you.
He makes snide remarks about the "low pay" of these people in a way which strikes me as classist and then makes even uglier remarks about how they deserve his treatment for not up and quitting which he claims they can do "at any time". He damns them coming and going, which does nothing to convince me he was even civil. Everything he wrote paints a picture of an individual with a chip on their shoulder who is actively looking to create such a confrontation. In his own words: "But that’s a small price to pay to remind these thugs that their powers are limited and restricted." So his stated goal was not to simply exercise his rights. His stated goal was to "teach them a lesson", in essence. That kind of goal is generally rife with unstated hostility.