As others have noted, the article doesn't seem to answer the question it poses. What's missing is more detail around the process of producing green and black olives.
Black olives enter the canning facility unripe and green. Bubbling air blackens them.
This part of the process isn't mentioned at all in the article, and it's hard to know whether this was the process being used by Freda Ehmann, or whether/how this oxygen treatment resulted in the botulism cases.
If you read into this more, it's actually the lye solution which artificially ripens the olive. That Youtube video doesn't go into the lye process other than the chart that you can see on the wall while going over the 7 day process. My guess is they don't really want to be verbal that lye is used (sounds a little gross to me).
However, the gap between why black olives are prone to botulism and green olives are not prone is not covered. I wish that was expanded on.
Watch the end of the embedded video:
https://youtu.be/xKWBJkaoRjM?t=1m7s
Black olives enter the canning facility unripe and green. Bubbling air blackens them.
This part of the process isn't mentioned at all in the article, and it's hard to know whether this was the process being used by Freda Ehmann, or whether/how this oxygen treatment resulted in the botulism cases.
All in all, not the best in technical reporting.