I think he said he had a very big velocity change, and that's what led him to pull bullets and check charges. And they also had different brass. I understand why they might need to use different powders, but how does it end up in the same lot, and in the same box?I hate to say it, but this is NOT unusual.
Ammo makers use whatever powder they have on hand that gives them their desired ballistics, so different powders definitely get used and ammo from one line MAY get mixed up with ammo from another line.
Working at ADI, I saw the change of powder and it takes several runs before the entire line is on the same powder.
The computer operating the system knows when the lines are flushed and starts dispensing the new charge weight and powder. So some cartridges prior to this are still on the line for boxing ahead of the newer dispensed rounds, so I can see how it happens.
That ball powder in the video is most likely bulk powder 789. Very common factory powder. The stick powder looks like bulk 4831.