Other mistake: Travis built a special arm holster for a gun that allows him to pull a gun easily, popping it in hand while his arm is already outstretched. It's the weapon he prepared for in the iconic "You talkin' to me?" scene, and practices handshaking with it. We see a scene when he prepares to go kill the Senator cutting the sleeve of the shirt off. And yet, when the actual attempted hit is shown, Travis has his hand (the gun hand) inside his jacket, alerting security. (01:36:30)
Sammo
Chosen answer: One theory about the end of the film is that it is Travis' dying thoughts, but this is not the view of Scorsese or writer Paul Schrader...they intended the ending to be ambiguous and an ironic critique of the media's, and the public's, reaction to and interpretation of violence (Travis is hailed as a hero for rescuing Iris, but we can imagine a very different reaction had he followed his original plan of assassinating a senator). Interestingly, when the film was originally shown on television, the following "disclaimer" of sorts accompanied the closing credits: "In the aftermath of violence, the distinction between hero and villain is sometimes a matter of interpretation or misinterpretation of facts. 'Taxi Driver' suggests that tragic errors can be made. The Filmmakers."