The sample size is too small to make any generalisations
it is not reliable to base a theory of dreams, which is supposed to apply to all on the case of one person. It might be that other people do not use dreams as a way of symbolising traumatic experiences.
The Wolfman may only represent people with mental health problems
Even if we accept we can make some generalisations based on the Wolfman’s experiences, they may not apply to people with food psychological health. Everybody dreams but not everyone has mental health problems or traumatic life histories.
The study has a strong focus on the unconscious yet this is an abstract concept that cannot be observed or reported on by the person
Freud would have argued that analysing dreams is the way we test the unconscious but dreams are quire abstract and do not provide hard evidence.
There is no way of knowing that accuracy of the dream recall
only the Wolfman experienced the dream, and so it relies on him to remember it as accurately as possible. It may be that Freud was analysing content that was never really in the dream.
The study is too subjective
the results are accused of being one person’s view on the dream and therefore are very biased. A psychologist with a different theory could interpret the content of the dream in a complete different way.