In the building next to the importamt documents area, you can hear people complaining about their cars not being fast cars with guns galore on them. This is mocking the GTA Online community, in which there are plenty of heavily armed vehicles, some of which are anachoristic for the era the game was set in (Summer 2013)
The commander you can hold up will remove his outfit to reveal a shirt saying “ANITA IS GOD”, a reference to infamous feminist Anita Sarkeesian. The whole franchise is anti-SJW, so killing him has no impact on your stress and even nets you a requirement for 100% completion.
In one of the huts, you can hear two people saying “XJS cars are crap! Why did a Brit want us to have one?”, a reference to the infamous Top Gear India Special, where Clarkson remarks that Maharajas would have Jaguar XJS cars instead of Rolls-Royces if they were around.