In the UK, looking after your very own interest is the only way to go. Don’t fall for “team sacrifice” or “personal compromise” in the interest of the “big picture” as most organisational cultures theories are fuelling some companies.
This does not mean that you should not be flexible at work, on the contrary, be open to cover multiple tasks if you have the skills and time. There is a balance needed here to be created by capable people as the “big picture” usually makes you small and most of the time reduce you to insignificance at work. This is not a reality, it’s just a trick to keep you in tension and make you wonder continuously if you actually have some sort of job security. Human Resources personnel will make use of that trick in waves so they can make sure you still have some sense of achievement at the workplace.
As on the matter of principle, everyone at my workplace have no problem shouting that if something doesn’t feed their own interests (at any level, even not work related), then they prefer adopting a reluctant attitude.
There is no need to provide actual examples, as I always prefer not to judge by particular cases, but the principle itself. Having rules under which we can classify our actions will provide clarity and clear guidelines. By generating ad-hoc temporary rules for particular cases so they can be manipulated toward the “big picture” is manipulative, incoherent, and unfair.