Quote:

… if 'then' is not a conjunction, then 1 implies a causal relation.

--language user, but not prescriptivist



I would say that the causal relation is implied only if it were "[If h]e did this, then he did that." The "then" is optional, thus "If he did this, he did that" would imply a causal relation but "he did this, then he did that" would not.