He did have the tools, and he never tried.
For example, he never tried to use the same analysis techniques but point them in another direction to see if he got the same results.
He got the results he did by pointing his patients in the direction of seduction and parental lust. A basic test to see whether this was effective at diving the truth would have been to use the same analysis techniques, but directed towards finding evidence of childhood encounters with something ludicrous: fairies for example. If a substantial number of patients started to describe encounters with fairies he could reasonably have concluded that the techniques he used were not useful in diving the truth. Similarly, rather than analysing his patients for parental lust he could have analysed them for, say, necrophilia. Once again, if a substantial number of his patients started to report feelings necrophilia, he could conclude that his analysis techniques were faulty. This sort of testing doesn’t require any tools that Freud wasn’t already suing. Indeed, the best scientific testing uses precisely the same methodology that one wants to test, and changes just one variable.
The ironic part is that the tests I proposed were done, by other, within Freud’s own lifetime. And the falsified Freud’s ideas. However by that time Freud had become such a celebrity, because of his work with celebrities, that he had become *the *authority on psychiatry. Any theory that Freud did not endorse was almost certain to be pilloried. And Freud himself, being unscientific, clung to his theory despite knowing that it had been serious shortcomings.
That is the biggest reason for saying that Freud was unscientific. Not because his theory was based on flawed evidence, but becuase he insisted it was right regardless of the evidence.
Kinda hard to reconcile that with the fact that psychiatry has recognised repressed memory syndrome for over 25 years now, and there is no evidence at all that it is even possible, let alone that it exists.