"instead of an actual EV charger"

They are using a power cord, Level 1. It's household current. They essentially put in another electric dryer or garage refrigerator circuit.

The IRS has this: https://www.irs.gov/credits-deductions/alternative-fuel-vehicle-refueling-property-credit-for-indivi...

It includes an example with this explanation:

"new electric panel, and conduit/wiring are associated property directly attributable and traceable to the charging port. The associated property must be dedicated to the charger to receive the full credit amount."

They can use that outlet for anything else, when the car is not plugged in. It's not dedicated, because they don't have a charger installed.