This marks a secondary event that is asserted as the reason for the main event or state.
When a preposition like after is used and the relation is temporal as well as causal, construal captures the overlap. While since and as can also be temporal, there are tokens where they cannot be paraphrased respectively with after and when:
Question test: Explanation and its subtype Purpose license Why? questions.
Assertion of why something happens or is the case.