My own experience with those security guards is mostly positive, but I also had nasty experiences with some of them for no apparent reason. Most of them are great, but unfortunately there are some arrogant machos, who should not be doing this job in the first place. Let us not pass judgements until we have the whole context. What exactly hapenned? What was exactly said by all parties? Why did the soldier (who must have been through thousands of these checks before) refused this time?
I don't believe the security guards not the police. At least until there is a credible investigation. There is just too much of these kinds of incidents.