get on someone's case vs report

get on someone's case

verb
  • To lecture, berate, or complain to somebody, especially to find fault or criticize. 

report

verb
  • To make a formal statement, especially of complaint, about (someone). 

  • To write news reports (for); to cover as a journalist or reporter. 

  • To relate details of (an event or incident); to recount, describe (something). 

  • To repeat (something one has heard), to retell; to pass on, convey (a message, information etc.). 

  • To be accountable to or subordinate to (someone) in a hierarchy; to receive orders from (someone); to give official updates to (someone who is above oneself in a hierarchy). 

  • To show up or appear at an appointed time; to present oneself. 

  • To notify someone of (particular intelligence, suspicions, illegality, misconduct etc.); to make notification to relevant authorities; to submit a formal report of. 

  • To take minutes of (a speech, the doings of a public body, etc.); to write down from the lips of a speaker. 

noun
  • An employee whose position in a corporate hierarchy is below that of a particular manager. 

  • Reputation. 

  • The sharp, loud sound from a gun or explosion. 

  • A piece of information describing, or an account of certain events given or presented to someone, with the most common adpositions being by (referring to creator of the report) and on (referring to the subject). 

How often have the words get on someone's case and report occurred in a corpus of books? (source: Google Ngram Viewer )