I think you can report them to DT members to tag him with negative trust like "cheater" or you can report it to signature campaign manager with proof.
It's not a trust issue for DT members to deal with. Sounds like it's a "report to moderator" issue, as mentioned, but it's not really clear to me what's going on. Examples would be nice.
If someone is in a campaign and is legitimately post bursting, they'll get tossed from the campaign. I've seen it happen many times. I'm not sure why someone would write
reserved will add comment later
unless they're reserving a spot in a campaign or something. I've never seen anyone do that in a regular thread, and in any case I'm not even sure that's against the rules.