Technically not stealing, it's a legal workplace benefit. Possibly abuses the spirit of the policy and may get the policy changed if enough people do it, but he's only doing what he's entitled to.

And there's actually a good chance that PG&E is not being paid: most of the big tech companies have large solar installations covering the parking lot which power all the EV chargers, so they cut PG&E out of it entirely and produce their own power.

Yes, but PG&E is getting paid much less.

PG&E has special tariffs for meters that are used only for powering commercial EV chargers ("BEV1" and "BEV2"). They're about half of what a residential consumer would pay for an EV-only meter (the "EV-B" tariff).