CNBC reported:
Tesla employees detail problems with Model 3 battery production and quality control
Manual assembly includes: Bolting down and gluing the outer clamshells which is not a safety issue according to 2 Tesla engineer whistle blowers.
However, it also involves manually slapping bandoliers together which 2 Tesla engineer whistle blowers are voicing safety issues: Cells might be manually mis-aligned, too low, too high and the minimum gap between cells might be manually uncomplied which might cause a short or fire.
Tesla told CNBC ""Until we reach full production, by definition some elements of the production process will be more manual."
Additionally, Tesla dismissed the danger of manual assembly because if 2 cells are touching, "there would be absolutely zero impact, safety or otherwise".