I have just landed (in 6.2 of the client uploader) a more refined system for tracking overheal and overkill. The old model had some inaccuracies that could result in overkill not being detected even after a boss had its health reduced to 0. This situation should be relatively rare for overkill, so DPS numbers might go down slightly but not significantly.
Overheal is another story. A significant number of heals were being counted incorrectly as effective healing with the old model. The new system should correctly count those heals as overheal now. This means HPS numbers are going to drop compared to the existing numbers.
I kept the overkill changes (with fixes to make A8S not regress), but for now I’ve reverted overheal. I need more sophisticated tracking to really nail this down.
Re-upload it using 6.4 once it deploys. I had assumed the Brute Justice would come back from the downtime with the increased health, but apparently it comes back dead and then has the health jump. I put in a special case for it in 6.4 so in theory it should be fixed.