Danny Reagan's Worst Moment In Blue Bloods Season 4

Danny Reagan (Donnie Wahlberg) is a hard-edged and abrasive character on "Blue Bloods," a Detective First Grade in the NYPD, a single father, and the eldest brother of the Reagan clan. All of the Reagans, from patriarch Henry (Len Cariou) to the youngest son, Sean (Andrew Terraciano), exhibit many of the same traits. Strong, duty-bound, and honorable are the best of their characteristics, while their flaws include stubbornness, self-righteousness, and being prone to outbursts are some that audiences see. 

Danny exhibits the extremes of those traits on many occasions. He is the detective at the center of some of the most significant cases from season to season and sometimes has to make the most challenging choices, like arresting his friend in "Ties That Bind." The flipside of that coin causes him to be the most abrasive of characters throughout the series, bringing him into conflict with everyone around him at one point or another. The other side effect to these conflicting characteristics is the tendency to dance on the line that separates good police work and corrupt practices. 

Audiences often see this, as superiors and colleagues consistently admonish Danny for disregarding the rules and protocols to get to the bottom of a case. He seems to sleep soundly, knowing he is getting criminals off the street in his mind. But in Season 4, he made one terrible decision that could have had dire consequences.

One person Danny comes into conflict with most is his sister, Erin (Bridget Moynahan). As the Assistant District Attorney, many of Danny's arrests cross her desk, and she has to prosecute criminals based on Danny's evidence or lack thereof. In Season 4, Episode 1, "Unwritten Rules," Jamie (Will Estes) and his partner Janko (Vanessa Ray) respond to a jewelry store robbery where another police officer is killed. Danny is assigned the case and locates a witness. The older woman has difficulty identifying the suspect until Danny coaches her. Due to the shaky testimony and Danny's against-protocol handling of the witness, Erin is forced to release the suspect.

While Danny's actions put her at odds with him and sparks a very Reagan-esque argument with the law enforcement members of the family ganging up on Erin, it had a much farther-reaching impact. The conflict between Danny and Erin became a conflict between the NYPD and the prosecutor's office as police officers all over the city staged a "blue flu." This real-life union tactic amounts to an illegal strike, where officers all over the city call in sick in protest.

For Danny Reagan, his conflict with his sister and his need to be right — even when he was clearly in the wrong — likely caused the undermining of cases all over the city. His zeal for putting away one criminal may very well have kept a dozen more on the streets of New York, making it one of his most selfish moments in the show.