So, you seem to be describing someone who claims to hold a philosophical belief, but doesn't actually do so.
How would this be different if the character claimed to be Lawful Good, but didn't put that into practice?
In further posts I expressed the issue of Values.
Consequentialism states that the outcome dictates the morality of an action. Does the outcome create the least harm/greatest pleasure/whatever. Right? But as a moral framework it relies on the people who hold it to create the values which are "Good" or "Evil". And that moral valuation is dependent on the society involved.
What is "Harm" to a given individual? Some may value a traditional society more than the people who make it up, and oppose any change to that society. Even when that change would be better for a subset or even the entire society because it breaks with what they consider more important: Maintaining the Traditional Society.
Such a person may even claim, and mean, that they love the people their actions are causing continual harm toward, but their adherence to tradition makes change impossible, regardless of the cost. Because their valuation is skewed to support society above other forms of harm.
Big part of why no singular moral philosophy works for everyone, even within a given society. Moral Philosophies are Proscriptive and try to shape how things should be, but rely on everyone agreeing on that baseline consideration of Value.
As to Deontology, we could spend years arguing over individual rules and exceptions and miss out on countless little ways that people could find to be cruel and wicked while still following every rule we create.
Oooh, you must have missed the early years (1e and before, but especially 1e). Penalties for violating or changing your alignment were a big deal back then. I'm at my girlfriend's house right now and don't have the 1e DMG in front of me, but I believe it cost you a level. Like, you went down a level when you changed alignment.
I wound up playing 1e after several years of 2e. But in the end it's the same thing: Applying a cost to a significant change to yourself. Losing something as your moral identity grows.
It sucks. But it's still descriptive because you -can- change. It's just that change is hard.