I think the point was that stealing energy is likely to be seen as a crime in general, not that this specific law applies to this specific hypothetical.
In general stealing anything is frowned upon and is at best a temporary imbalance in technical ability to steal versus economic incentives to stop theft.
Someone using a VIN spoofer to free-ride or enjoy lower rates on Tesla's supercharger with their own vehicle is definitely acting unauthorized.
Besides, courts have ruled that even charging a phone at your workplace without authorization fulfilled the criteria, the case was only thrown out later on because firing someone over stealing 1.6 cents worth of electricity after 19 years of employment is ridiculous [1].
Yes, but unauthorized is not what the law says. The law is about using a wrong conductor to steal energy. Not the case when the charging hardware is not modified.
Some jurisdictions take stealing energy as a crime. Germany, for example, has up to five years of prison on the books [1].
Kids, don't mess around with energy if you don't exactly know what the f..k you are doing and know the legal and technical risks involved.
[1] https://www.gesetze-im-internet.de/stgb/__248c.html