"Treatment killed Covid patients" is the new "Jewish doctors plot."
In the Middle Ages, many of the best doctors were Jewish (for various societal reasons). When an important person was really sick they'd call in a prominent Jewish physician. But because they were called as a last resort, and due to the primitive state of medical care overall, patients still often died.
So Jewish doctors often got blamed for "intentionally killing" their patients. For people who can't admit Covid killed, they've got to concoct a conspiracy theory blaming something else.