That's what I was thinking too, and really very few if any of these were planned to be a fraud from the start. It would be more interesting to see slide decks of people who knew from the start they would defraud their investors, instead of companies like SVB who focused too much on diversity instead of risk assessment or Lehman Brothers who collapsed during a recession.
I can't speak for the other pitch decks, but to anyone with any knowledge of how medical testing works in practice, Theranos was a clear fraud from day 1. This derives from the simple observation that almost all current blood tests eventually measure only a small sample (microlitres) of the blood initially drawn, and the business proposition didn't address the question of why larger samples are normally drawn (a lot of the answer lies in the "engineering" problems inherent in handling complex biological liquids).
Obviously, the Theranos deck wasn't pitched to people with the requisite knowledge...
After seed round anyway, a red flag was a combination of the technical hand waving and having the wrong sort of board for the product. In earliest decks you can only really look at the team anyway. I'm not sure you could reliably discount them in the first 6 mo, say.