Uh yes that is exactly how it works. Not only in the UK, but across the western world. You have civil law (to sue private companies) and administrative law (to sue public companies). The idea behind the latter is that the public sector is so busy "helping" the public, we should not really bog them down in complex litigation, hence we assume that the public sector has the public interest at heart and will never lie, so there is no need to have a full fact-finding legal process, so lets just take what they say as the facts and see if anything wrong took place. It will not shock you to learn that every fucking cunt in every fucking administrative role shows up to court and rattles off lie upon lie upon lie.
You assume that everyone working in Public Sector Admin is a horrible lying cheating scumbag, while everyone working in the private sector is pure of heart?
How deliciously mental of you.