If this is genuine, then I'm afraid I think the Guardsman was wrong. Of course I understand his frustrations but it's still wrong. What he did undermines our armed forces.
Being provoked is something military people are trained to deal with aren't they? You're supposed to follow orders and not be deviated by idiots like that student. If you didn't the whole military ethos would collapse.
Furthermore, now this is in the public domain, surely only more idiots, and I include some media elements here, are likely to make additional attempts to undermine our services.