MyBB

If you delete multiple posts using "Inline Post Moderation" then any reported posts are not marked as reportstatus 0.

If you delete a single post using "Inline Post Moderation" then the report is properly marked as reportstatus 0.

To replicate:

1. Find a thread with more than 2 posts.
2. Report post #2.
3. Using "Inline Post Moderation" delete posts #2 and #3.
4. View reported posts and see the deleted post still there with no info

To View Normal behavior:
1. Find a thread with more than 2 posts.
2. Report post #2.
3. Using "Inline Post Moderation" delete post #2
4. View reported posts and see it's marked

Problem:
moderation.php

    case "do_multideleteposts":

        // Verify incoming POST request
        verify_post_check($mybb->input['my_post_key']);

        $postlist = explode("|", $mybb->input['posts']);
        if(!is_moderator_by_pids($postlist, "candeleteposts"))
        {
            error_no_permission();
        }
        $postlist = array_map('intval', $postlist);
        $pids = implode(',', $postlist);

        $tids = array();
        if($pids)
        {
            $query = $db->simple_select("threads", "tid", "firstpost IN({$pids})");
            while($tid = $db->fetch_field($query, "tid"))
            {
                $tids[] = $tid;
            }
        }

        $deletecount = 0;
        foreach($postlist as $pid)
        {
            $pid = intval($pid);
            $moderation->delete_post($pid);
            $plist[] = $pid;
            $deletecount++;
        }

        // If we have multiple threads, we must be coming from the search
        if(!empty($tids))
        {
            foreach($tids as $tid)
            {
                $moderation->delete_thread($tid);
                mark_reports($tid, "thread");
                $url = get_forum_link($fid);
            }
        }
        // Otherwise we're just deleting from showthread.php
        else
        {
            $query = $db->simple_select("posts", "*", "tid='$tid'");
            $numposts = $db->num_rows($query);
            if(!$numposts)
            {
                $moderation->delete_thread($tid);
                mark_reports($tid, "thread");
                $url = get_forum_link($fid);
            }
            else
            {
                mark_reports($plist, "posts");
                $url = get_thread_link($thread['tid']);
            }
        }

        $lang->deleted_selective_posts = $lang->sprintf($lang->deleted_selective_posts, $deletecount);
        log_moderator_action($modlogdata, $lang->deleted_selective_posts);
        moderation_redirect($url, $lang->redirect_postsdeleted);
        break;

Seems a logic problem. Whatever the solution you choose there is a small bug here.