Other mistake: Eddie and her partner respond to a store selling sandwiches with contradicting prices. For example, grilled cheese is listed for $3.99 and $6.25, and tuna melt is $5.50 and $5.99, and BLT is listed twice on the same sign. (00:03:10)
Blue Bloods (2010)
1 other mistake in season 12
Starring: Tom Selleck, Bridget Moynahan, Donnie Wahlberg, Len Cariou, Will Estes

The Uniform - S2-E11
Character mistake: While handcuffing an auxiliary officer in his apartment, there is a poster on the wall reading, "attention military personal..." Personal is misused. It should read "attention military personnel." (00:16:02)
Frank Reagan: I'm the PC. I know everything.
More trivia for Blue Bloods
Question: What is the significance of the lapel pin worn by detectives on Blue Bloods?
Answer: It is an NYPD Detective Bureau lapel pin. If you zoom in on a pic of "Danny Reagan," you will see that the pin has the letters DB on it.





Answer: It is the lapel pin worn by members of the NYPD Honor Legion.
The lapel pin is on Danny but not Biaz, why? Also, Baker, Sid, Frank &Garrett wear one. Significance? Are they all the same?
Is the P.C.'s pin different than a legion pin? What are the symbols and their meaning?
I think it may be Masonic?
But why would the mayor wear one?