You have chosen a very narrow definition of the word harm. You left out a lot that applies:
-actual or potential ill effect or danger.
Possible exposure to covid is definitely potential danger. Possible damage to the vehicle is harm.
-have an adverse effect on.
They wasted his time and insulted him. Those are adverse effects. I don't know how much your time is worth, but mine isn't cheap.
Then there is the legal version of harm:
-any injury, loss or damage. It can also be any material or tangible detriment.
As discussed above, he lost time. In addition, he lost use of his vehicle. If someone wants to use a vehicle that belongs to someone else, they generally have to pay for that privilege, so that is money and wear that was lost.
So, sure, by your definition, there was no harm. But by generally accepted definitions, the OP has obviously suffered harm.