When a post/topic is in needs approval and a Staff chooses to Reject the post/topic, nothing gets logged. You don’t get an action stating the post/topic was deleted, or by whom, the post just vanishes and the user is left Silenced.
Log of post/topic entering Needs Approval Queue
Staff clicked the Reject button.
No additional logs were added (at the very least, it should log the post/topic being deleted).