Lettuce has a shelf-life of ~4 weeks from harvest, the parasite can incubate for ~2 weeks from consumption, and it may take a week or two for the infected person to see a doctor, get positive test results, and have those results reported to the tracking bodies. That means tracking could easily lag distribution of the bad goods by 2 months.

Operating company that contributes heavily to the Republican administration. Owner of said company went to the White House to have said administration walk back the findings that they are the source of explosive diarrhea. Administration firing a chunk of the staff responsible for tracking and recalling products that cause explosive diarrhea. Administration having folks who don't understand science or health and don't believe in facts in charge of science and health.

This was all expected and will continue

So, tfa does not really cover this in great depth but it looks like it is mostly over in terms of new cases, at least just looking at the graph. Maybe though it is just a time delay between new cases and reporting.