In season 3 (8 Mar. 2013), Whitney Robshaw tells Frank Reagan that they had met at Erin's 40th Birthday, so there for it cannot be Erin's 40th in November 2015.
(at around 48 mins) Danny's phone switches between left and right hands between shots.
At 34:15, Danny is holding his phone with his left hand while holding the steering wheel with his right hand. He is driving at a high-rate of speed. The next shot the phone is now in his left hand, and the right hand is holding the steering wheel.
In Season 3 Episode 17, Frank meets one of Erin's friends for the second time, their first meeting at Erin's 40th birthday party. However, in Season 6 episode 7, at the start of the episode she talks with her daughter Nikki about the worries of turning 40.
As well as already mentioning that Erin had already turned 40, in season 5 ep.10 (Sins of the Father), Erin said that when the murder in question happened in 1976 she wasn't born yet.
The Black Dodge Charger, near the end, was a 69 model. The dialog said that it was "like" the one from "Bullitt". Factually wrong . The one in the movie was a 68 R/T model. The grill & tail lights changed on the 69 model. The grill on the 68 did not have a chrome piece in the center and the tail lights on the 68 were 4 round lights whereas the 69 had 2 long rectangular tail lights.