Took the time to read up on
Antigravity's website. Turns out it's a bit of both:
So they have their protection circuit set to cut off at 12V which is rather high, but the objective is so that the battery doesn't dip below 8V when cranking. You could say if the objective was only to prevent over discharge then it could have been set at 8V which I assume is when the internal cells will be at their lower bound of 3.0V, the tradeoff being the battery protection circuit will likely engage while trying to crank.
IMO they purposely set their protection circuit voltage higher so there is always enough juice left to crank, as the guy presenting the build video also claimed.