The strength of the method is precision; its vulnerability is the relevance of the analogy. Real situations contain responsibility, relationships, uncertainty, and alternatives that a case may bracket. A careful reader identifies the exact inference under examination instead of treating an intuitive response to one scenario as a complete policy argument.
To read a Thomson-style argument, identify the premise granted for discussion, the inference challenged, and what remains undecided. A thought experiment can refute a claimed implication without proving every conclusion on the wider topic. Test the argument by changing responsibility, consent, or the relationship between the parties. The method becomes stronger when a critic explains why a difference matters morally, rather than merely observing that no invented story exactly duplicates a real situation.