You literally have no basis to even determine if a log being submitted is way below what should theoretically be possible by competent play or not.
Except you do.

Logs taken into account for dps numbers are KILLS, which gives you multiple easy confirmation points. Non-kills are kept off those breakdowns and attached to the users kill submission (if any) for reference by the submitter and submitters group.

You have to submit the logs as is, tied to an specific account uploading it. If someone is posting substantially different parses than everyone else (and if you're moving the damage off of one class, it has to be moved ON to someone else, which would also make THOSE numbers substantially different), the damage would still have to work with the kill time mentioned, AND every one of those bosses enrages, so you have a minimum raid damage threshold you have to meet.

Additionally, it would be seen as instantly suspicious when you have a party with someone doing that poorly over that many kills.


The amount of effort you would have to put in to altering logs in a convincing way to boost or tank something even a little bit would be considerable.