The article on "Expertise" believes in the theory of Empiricism, rather than nativisim. One must put in long hours of practice for acquisition of complex knowledge. One is just not born with these skills. The articles says that the skills are domain specific, and the expertise is only restricted to that particular domain in which the expert has put in a lot of effort.
Detection of co-variation between events is the deep principle in implicit learning. With each new experience, an expert learns something. Article on "Expertise" talks about domains where beyond a certain point, no more growth of an individual takes place. He then targets some "specific areas" where he may be lacking. This can be explained by the fact that implicit learning relies on learning co-variation between events but these specific skill sets are not covered very frequently in practice sessions, hence they evade the learning process.
People do not use their rational and logical faculties to solve decision problems in their day to day lives. Decision making is based on implicit knowledge. This is one of the belief system that can be used to explain expertise. Afterall, a Rubik's cube expert solving such a high dimensional problem in so less time is hard to explain if we assume he is thinking of all possible moves to take after each rotation he does. A lot of experience is needed to "blank out" all the wrong moves, and it is being done subconsciously. He does not even think of the wrong moves.
But is the initial phase of learning subconscious? Implicit learning does not speak anything about skill learning. Reber believes in the view of R.Anderson(Anderson, 1976) on procedural knowledge. To begin with the learning is conscious but slowly and steadily, the subconscious takes over decision making.
The article on "Expertise" also taks about the difference in organisation of knowledge and its representation in the brains of an expert and a novice. Frequent recalls while practising strengthen the associations in long-term memory and helps in better encoding, storage, and retrieval of information for future use.