The reason Tina Huang left during "Misconduct" (Season 6, Episode 5) was that "...the "Rizzoli & Isles" writers made the decision to write the character out for the sake of creating a dramatic and personal case for the lead characters to solve."
Last appearance of Tina Huang as Criminalist Susie Chang as a prominent background character
Maura is notorious for her inability to lie without breaking out in hives and even fainting. Yet, when Jane accuses her of sitting around the house doing nothing, she is actually sitting and says she isn't without suffering any aforementioned consequences.
This is not the first time Samantha Smith has played a character named Mary. She plays Mary Winchester on and off again throughout the 15 season run of Supernatural.
Maura refers to the governor as Governor Holcomb. However, in 2015, when the episode aired, Charlie Baker (R) was governor of Massachusetts. Changing the names of high level politicians/leaders is a common practice in TV shoes and movies, especially when the characters interact with the politician/leader.