While I might quibble with the "very", beef is a rare vector for e. coli infection, even based on this limited outbreak list: https://www.cdc.gov/ecoli/outbreaks.html To some degree it makes sense, because people have been conditioned to treat meat as a disease vector and tend to treat it more carefully than greens and other plant products.

Also, highlighting a single Cargill outbreak says nothing either way about the correctness of "very rare".