Your second link gives me an error: "The specified request cannot be executed from current Application Pool".

The first link doesn't appear to me to justify the statement that "of course not all libertarianism is 'contra causal'". The Wikipedia article makes reference to a class of libertarian theories that don't involve a non-physical mind overriding causality, but the only example of such a theory it says anything about is Kane's, and it's far from clear to me that Kane's notion of free will is really libertarian (for the reason given in the article and ascribed there to Randolph Clarke).

If you define "libertarianism" as meaning only that free will and strict determinism are incompatible, then I agree and probably Luke does too: "of course" libertarianism needn't be contra-causal. (Well ... I suppose it depends on exactly how you define "contra-causal". I'd have thought that with that definition of "libertarianism", it would be natural to define "contra-causal" as "not deterministic", and then libertarian free will --> contra-causal free will after all.) But someone who believes, e.g., that free will = determinism + chance is "libertarian" in that sense, and that's surely neither what Luke had in mind nor what most other people have in mind when they talk about (metaphysical) libertarianism.

(I don't much like the term "contra-causal", though. After all, libertarians commonly don't say that free choices are uncaused but that they (and not, e.g., any merely physical process) caused those choices. "Contra-physical" would get nearer to the heart of the matter.)