Near the end of the episode, Shawn is wrapping up and telling Jordan Beaumont how horrible his day has been. He says, "The girl you're dating turns out to be your sister who killed your father who killed your mother and was sleeping with your ex-girlfriend." But his father did not kill his mother, his father killed his half-sister's mother.
The running joke of Henry needing to stop to tuck in his pants fails once when he is climbing the stairs at about 10 minutes in. His shirt is untucked as he comes up the first flight but then when immediately shown ascending the second flight after reaching the landing, his shirt is tucked in.
Thia determines that Ellis is her biological father (and thus her mother's killer) due to his colorblindness, a trait she shares. During Shawn's speech at the reveal, Shawn states that "Color blindness is a genetic trait that is almost always passed on from father to daughter." In fact, though the daughter will most likely inherit the colorblind gene from her father, the chance of a daughter actually being colorblind is very slim. Thia's mother would also have to have been a carrier for Thia to even have a chance at also being so. In general, colorblindness is extremely rare in females. According to the NIH, only about 0.5% of women of Northern European ancestry suffer from it. A quick internet search will be able to explain the genetics behind colorblindness far better than is possible in this little blurb.
At the beginning of the episode (after the credits and commercial break), The Chief is questioned by reporters. There is a CXRA news truck and one of the reporters is carrying a mic with the call sign letters CXBX. Neither seem to be "real" television stations - but more importantly, the "C" is used for call signs assigned to Canada. Hightly unlikely that one, let alone two Canadian local news outlets would be covering this case.
In talking with Bea about her late husband Lou, Henry asks, "Do you remember back in '91, hearing Jack talk about a case involving the name Veronica Towne?" "No. He rarely talked to me about any of his cases." "Do you remember anything strange about his behavior at the time?" Jack was the name of one of the other guys Henry and Lou worked with back in the day.