Consumers were poisoned by tainted beef while federal inspectors dithered and the Department of Agriculture withheld crucial information from the public, according to a federal report. The review of the biggest beef recall in Canadian history lamented the “underwhelming” competence of XL Foods Inc.,the Alberta slaughterhouse that was the focus of the scare, and the lack of urgency by meat inspectors: “Did 18 people need to get sick? Did so much meat have to end up in landfills?”