Yeah, but if you measure actual bike's battery that's good and fully charged from properly working charging system that's been sitting overnight, it will be over 13v. Especially if he just hopped off after a ride to deliver food. After 30s off, it should be over 13.5v. It actually takes many days for good battery to drop to resting voltage. Test yourself to see.
Here's my 250 after 2-days sitting (all factory OEM charging system).
And my VFR's old lead-acid bat after sitting a week
VFR's new lithium battery after sitting for 2-weeks
Also my RV's batteries go from 13.6v when put into storage, drops to 12.5v in 3-weeks.
This chart's more accurate: