Isso é abordado no roteiro de filme ;
A implicação é que, na ausência de Marty, o médico teria encontrado Clara na estação, impedindo-a de cair no canyon. Ela teria então pago por sua lápide quando ele foi baleado.Mayor: [Coming just inside the door] Excuse me Emmett. You remember last week at the town meeting when you volunteered to meet the new school teacher at the station after she came in?
Doc: Oh yes, quite so.
Mayor: Well, we just got word she's comin' in tomorrow. Here are the details for ya. [He gives Doc a sheet of paper]. Thanks for all your help.
Doc: Walking towards Marty, calling out. Anytime, Hubert!
Mayor: Oh, her name's Miss Clayton. Clara Clayton.
Doc looks up in a state of confusion, putting two and two together. The Mayor leaves before Marty finally speaks.
Marty: Well, Doc, now we know who Clara is.
Doc: [Looking at Marty with a weird grin on his face] Marty. It's impossible. The idea that I could fall in love at first sight? It's romantic nonsense. There's no scientific rationale to that.
Obviamente, isso leva à questão secundária de porque o Doc ainda se lembra dela como 'Clara Canyon' , mas não há nada a dizer que ela não poderia ter caído mais tarde. p>