The basins do not hold the full amount of engine oil that bikes do use or contain within the motor plus when the bike lets go, under some circumstances the oil can be thrown/flow out the exhaust or in extreme cases if the motor lets go in a big way it can hole casings (extremely rare in bikes - cannot recall the last time this occurred without an accident first)
Maybe true, but in bikes once you know the damage you get off the racing line and where possible onto the grass at a marshall point.
VR clearly is disappointed when it lets go but to then maintain on the track is poor form. It would actually be interesting to see at what point after the smoke starts does the engine get shut down (have yet to see the full race)
That all said, this happens so rarely now one wonders if the riders even remember the courtesy of reactions when it does (admittedly JL has not forgotten)