He is under no obligation to report anything to the the JD
WRONG! The law is the law and he is required to by the law.. Failing to report this at the time of incident (or shortly thereafter) is a crime. So he either perjured himself or he broke the law... Which is it?
The law is the law.
Do you actually know the law in question, or did you just hear someone on the radio tell you what the law is?
Comey is required, by federal statute, to report any 'interference in' or 'request to stop' an ongoing investigation to his superiors. Those superiors would be the DOJ chief or his assistant.
https://fas.org/sgp/crs/misc/RL34303.pdf
"Obstruction by Intimidation, Threats, Persuasion, or Deception (18 U.S.C. 1512(b) The second group of offenses within §1512 outlaws obstruction of federal congressional, judicial, or administrative activities by intimidation, threat, corrupt persuasion, or deception, 18 U.S.C. 1512(b). Parsed to its elements, subsection 1512(b) provides that: I. Whoever II. knowingly A. uses intimidation B. threatens, or C. corruptly persuades another person, or D. attempts to do so, or E. 1. engages in misleading conduct60 2. toward another person, III. with intent to A. 1. a. influence, b. delay, orc. prevent 2. the testimony of any person 3. in an official proceeding,61 or B. cause or induce any person to 1. a. i. withhold testimony, or ii. withhold a (I) record, (II) document, or (III) other object, b. from an official proceeding, or 2. a. i. alter, ii. destroy, iii. mutilate, or iv. conceal b. an object c. with intent to impair d. the object’s i. integrity or ii. availability for use e. in an official proceeding, or 3. a. evade b. legal process c. summoning that person i. to appear as a witness, or ii. to produce a (I) record, (II) document, or (III) other object, iii. in an official proceeding, i.e., a (I) federal court proceeding, (II) federal grand jury proceeding, (III) Congressional proceeding, (IV) federal agency proceeding, or (V) proceeding involving the insurance business; or 4. a. be absent b. from an official proceeding, c. to which such person has been summoned by legal process; or C. 1. a. hinder, b. delay, or c. prevent 2. the communication to a a. federal judge or b. federal law enforcement officer62 3. of information relating to the a. commission or b. possible commission of a 4. a. federal offense or b. [a] violation of conditions of i. probation, ii. supervisor release, iii. parole, or iv. release pending judicial proceedings; shall be fined under this title or imprisoned not more than 20 years, or both.63 In more general terms, subsection 1512(b) bans (1) knowingly, (2) using one of the prohibited forms of persuasion (intimidation, threat, misleading or corrupt persuasion), (3)(a) with the intent to prevent a witness’s testimony or physical evidence from being truthfully presented at official federal proceedings or (b) with the intent to prevent a witness from cooperating with authorities in a matter relating to a federal offense.64 It also bans any attempt to so intimidate, threaten, or corruptly persuade. 65 The term “corruptly” in the phrase “corruptly persuades” as it appears in subsection 1512(b) has been found to refer to the manner of persuasion,66 the motive for persuasion,67 and the manner of obstruction.68"
Then we have departmental regulations which implicitly directs what shall be done..