Re: They were not.
No, they compared a Nissan Leaf to a Hyundai i10 to make a statement about cost difference.
That's as valid as making a cost comparison between any two other vehicles.
If you have two identical spec cars from the same manufacturer, same trim but one is an EV and one is a Petrol and the EV promoter states that it is much more cost effective. It makes sense to compare cost of the vehicle and total running costs to point out if the ICE is cheaper over 140,000 miles. Otherwise it is meaningless.