I believe the issue of falsely labelling certain oils with "synthetic" may very well be one of many causal factors in sludge reports.
The real causes of the Toyota specific issue are still unknown, and there has been a tremendous amount of speculation about it over the years.
I disagree with Charlene Blake's narrow focussed assessment of the sludge problem.
She blames Toyota exclusively, where in fact the issue is a complex one with any number of possibilities.
Her frequent appearances on the net are characterized by generalities and politicized rhetoric which appear to be thinly veiled attempts to raise alarm by innuendo and inference.
When pressed for facts and verification, she craftily avoids these challenges, and when she does respond, it's always with more alarmist rhetoric.
The absence of factual and verifiable evidence in any of her remarks is conspicuous; it certainly doesn't point to credibility.
While I hesitate to use the term 'lies' in describing much of the rhetoric she liberally dispenses, I must say it seems she does take some pretty wild liberties with the truth!!