Upvote:5
This question is somewhat borderline for Travel, but you've focused on the wrong distinction.
The Lexus RX450h does not have a gazole/diesel engine.
The RX line has an essence (gasoline/petrol) engine, in all versions manufactured for all markets around the world through at least the 2016 model year.
In recent model years, premium fuel with an octane rating (indice d'octane) of 95 (Europe; equivalent to 91 in North America) is recommended, but putting diesel of any grade into a petrol/gasoline engine will entail time at the repair shop.
In the U.S. and Canada, unleaded nozzles are smaller than diesel nozzles to prevent such accidents from happening, and I would have thought the same would be true in Europe, where diesel cars are much more common. On the other hand, if the gas station was small and old as you say, maybe they swapped parts to try to save money.
You probably didn't experience problems early on if you were filling up with premium diesel. In contrast to octane in gasoline, high cetane makes diesel easier to ignite, and the Lexus engine has a high compression ratio (13:1 in the 2016 US model), making it possible to start. It sounds like once you filled up with regular diesel, the fuel was no longer combustible enough.
Also, diesel hybrids are, at this writing, still uncommon. Diesel engines already get much higher mileage than their gasoline-powered counterparts, and are more expensive to produce, so the relative benefits and demand for such cars is lower than for conventional diesels or for gasoline hybrids.