I believe the answer is: It is due to something unusual about Jake, because his behavior is low in consensus, low in distinctiveness, and high in consistency.
When average people observe a certain action, people would judge how majority of people would do that action and make their judgmeent based on what considered to be normal.
Since jake action's is not being done by many people (low concensus) and tend to be rarely spotted in class (low consistency), people would automatically assume that something is wrong with jake, even if in fact nothing wrong with him and he do it in all class.