Back in the day before Tesla went mass market, Elon included lifetime free charging at Tesla superchargers - so yes
@gzoom will have been able to use free charging.
If
@gzoom had had to pay and only charged at Tesla superchargers, and the rate was 48p per kwh (current UK rate), he would have spent £502 on electricity.- so £133 less than petrol according to his estimate.
He was in Norway though for a large part of the journey, so the rate there is 22p per kwh - if he had only been in Norway that would reduce the cost to £230. Out of Norway, Denmark and Germany, Denmark is the most expensive at 30p per kwh which gives a total spend using tesla superchargers only of £313.80
It is likely however that
@gzoom will have had access to a variety of charging. Some hotels will have free charging for guests, or if using AirB&B then probably included in tariff. Even if he was paying for electricity it is likely that it would have cost him less than half what it would have cost for Petrol.
The above is also an illustration of how countries with green incentives make owning an EV even more desirable.