Violation of 8.4(a) and 5.3(c)
Later in the episode, Harvey tells Mike he knows that Mike has been keeping a briefcase full of pot inside a file cabinet at Pearson Hardman. The amount of marijuana Mike has in the briefcase seems like it would lead to a felony drug possession charge. Now, this probably wouldn't be a violation of MR 8.3 because Mike is not a lawyer and 8.3 seems to only apply to other lawyer's misconduct. However, felony possession of marijuana is probably a violation of 8.4(b) as it is a "criminal act that reflects adversely on the lawyer's honesty, trustworthiness or fitness as a lawyer in other respects." Therefore, even though Mike is not a lawyer he is using the firm's filing cabinet to hide the marijuana, and so Harvey may be criminally liable for knowing that Mike was using his firm to hide marijuana without reporting him. Therefore, if Harvey were to be criminally liable in New York for failing to report Mike for hiding marijuana at his firm, then Harvey himself might be violating 8.4(b) because this may impact his trustworthiness or fitness as a lawyer by concealing Mike's possession of pot.
Regardless of that outcome, Mike's violation of 8.4(b) is a violation of the rules of professional conduct, and so Harvey may now be in violation of 5.3(c) AND 8.4(a). Let's go through 8.4(a) first: 8.4(a) states that it is professional misconduct for a lawyer to "violate or attempt to violate the rules of Professional Responsibility, knowingly assist or induce another to do so, or to do so through the acts of another." It could be argued that by not reporting Mike, he was helping Mike conceal his pot, and therefore he was knowingly assisting Mike to violate the Rules of Professional Responsibility. Second, Harvey is in violation of 5.3(c). 5.3(c) states that a lawyer shall be reasonable for the conduct of a nonlawyer (here Mike Ross) when a lawyer, with knowledge of the specific conduct, ratifies the conduct involved. Here, Mike is probably violating the rules of professional conduct by hiding felony-degree amounts of marijuana in his law firm's filing cabinet, and Harvey, who has knowledge of that fact because he says he "knows what's in the briefcase" has arguably ratified that conduct by not confronting Mike or reporting his conduct earlier.
Possible violations of 4.3 and 8.4(b)
Near the end of the episode, Harvey visits Joanna Webster, a fake employee who hurt his case, and threatens her with jail time if she doesn't tell him the whole story. Here, Joanna Webster is unrepresented- there is nothing in the show to suggest that she is represented by another party in the litigation to which she is a witness to, even though Harvey suspects she is working for the other side to throw off his case. He tells her to tell him the whole story. If advising a witness to tell a lawyer the whole story is legal advice, then he is probably in violation of 4.3. 4.3 states that "the lawyer shall not give legal advice to an unrepresented person, other than the advice to secure counsel, if the lawyer knows or reasonably should know that the interests of such a person are or have a reasonable possibility of being in conflict with the interests of the client." Here, because Harvey suspects that Joanna Webster is working for the opposing party by throwing off his case, he knows or reasonably should know that her interests are adverse to his party's interests. Therefore, asking her to tell him the whole story, if construed as "legal advice" is him giving legal advice to an unrepresented person with interests adverse to those of his client, and is a violation of 4.3. He also tells her that "Here's what you're gonna do..." before the scene changes, suggesting he gave her legal advice. Additionally, Harvey says that he doesn't have the wire transfer showing that the company paid Joanna Webster to lie, but once he does, she will be going to jail if she doesn't talk to him. This means he doesn't yet have knowledge, only a strong suspicion, that she is working for the other side. In some jurisdictions, threats like these without facts can amount to extortion and so he would also be in violation of 8.4(b) as a "criminal act that reflects adversely on the lawyer's honesty, trustworthiness, or fitness as a lawyer in other respects."
Violation of 8.4(e)
At the end of the episode, Harvey suggests that he knows an old buddy from law school who is a U.S. attorney that would be interested in hearing this witness tampering case. He and Mike imply that because Harvey is so close to the U.S. attorney it should be no problem for the attorney to hear the case- they were so close that Harvey attended the man's wedding and bachelor party. This is a flagrant violation of 8.4(e) which states that it is a violation to "state or imply an ability to influence improperly a government agency or official..." Here, the U.S. attorney is a government official, and Harvey is implying that because they are so close, he will have an ability to improperly influence him into hearing the case. It could be argued, however, that Harvey is not saying that the attorney will be biased when he hears the case, but that Harvey is only suggesting that the U.S. attorney would hear the case. But it's pretty strongly implied that their close ties means that it will be an uphill battle for the other side to win their case if it goes to trial.
That wraps up the episode. Please feel free to enter any questions, comments or concerns you may have into the comment box below!