I'm sorry for the difficulties with your Landcruiser.
What was the case you were trying to win?
Were you trying to make the case that someone "dusted" your Landcruiser, or perhaps that oiled foam high performance air filter did not perform properly?
Google got a bunch of hits for "dusted" all related to particulate matter getting into the intake bypassing the air filter by various means.
Some hits sounded quasi main stream, perhaps even approaching customary.
So you ran it out of oil while towing, and the oil light came on?
And you had confirmed it was a the proper level before starting the trip ?
Or, when you first acquired the vehicle 3 months ago, you checked it, or assumed it was at the proper level and have been driving it ever since?
I seem to recall an old piston ring tech article saying a spoon full of grit, all at once or over time, would severely damage the cylinder walls and cause oil consumption and lost compression.
I think the appearance of the oil light would be a much delayed indication of excessive oil consumption, and lacksadaisical owner participation. Not a direct result of "dusting."
I doubt most kinds of grit directly dumped into the sump could take out bearing and cause enuff wear to lower the oil pressure to 3 psi or at whatever pressure the oil light comes on.