Isso é do script ...
DELAHUNT You know what I thought today? BILLY What's that? DELAHUNT Who didn't show up today is the rat. BILLY Yeah, so? DELAHUNT You never been late in your life. And when I called you... I made a mistake. I gave you the wrong address. But you showed up at the right one. DELAHUNT grips his arm. BILLY is terrified. DELAHUNT (CONT'D) Tell me why I didn't say anything. Tell me why.
Então, parece que vamos descobrir, mas ...
He waits for DELAHUNT to continue. But DELAHUNT after an odd smile of complicity, finally dies. BILLY, the only one who knows that DELAHUNT is dead, stares down at him.
Então, o escritor deixou para o público descobrir o porquê. Aqui está Scorcese discutindo , deixando a ambigüidade.
Os policiais pelo menos fingem Delahunt era um policial para tirar o calor de Billy.
As teorias são abundantes, mas apenas Delahunt sabe ao certo, e ele está morto.Delahunt was later shot by police after the murder of Oliver Queenan. He was bleeding on a couch at the gang's hideout when Fitz came over and told him that a doctor was coming but traffic was slowing him down. He called over Costigan and revealed that he knew Billy was the rat because he knew to go to 344 Wash even though Delahunt mistakenly told him to 314 Wash. Delahunt dies before he could alert the other gang members. The SUI plants a story on the local news that Delahunt was a cop, attempting to assure Costello that his rat was gone in order to take the heat off of Costigan.