How would you summarize the main points of the article "Police Mistakes of Law" by Wayne A. Logan? (http://law.emory.edu/elj/_documents/volumes/61/1/articles/logan.pdf)

Wayne A. Logan addresses in this article what he sees as a problematic trend that threatens individuals’ constitutional rights—courts condoning police mistakes of law. These mistakes of law occur when police wrongly stop or arrest someone based on incorrect legal understanding. Logan cites as a major concern that when courts excuse these mistakes of law, the exclusionary rule cannot be applied. This means that courts may permit evidence secured as a result of mistakes of law. This evidence often supports prosecutions of unrelated, more serious offenses, typically relating to guns or drugs. Logan argues for courts to return to what has historically been their no-excuse position of condemning police mistakes of law. The article seeks to bring attention to the significant role police play, not just as enforcers, but as interpreters of law.
Part I discusses two categories of police mistakes, constitutional and substantive law errors. Logan focuses on the latter, specifically in the context of police search and seizure authority. Part II argues that the justice system should incentivize police knowledge of the law, rather than indulging or excusing “reasonable” mistakes of law. Part III further examines negative consequences of courts deferring to incorrect police interpretations of law, including the violation of separation of powers because police, in effect, become lawmakers, rather than law enforcers. Part IV suggests as a solution improved police training in substantive law.