It's very common that HTML mail messages containing recycled copy from sources like news magazines contain wrongly-encoded characters. It often results from copy/paste operations from, say, word processors. An instance or two buried deep in a long passage of text will often escape the notice of whoever is tasked with proofreading pages before they're published, and when the copy is sent out to email subscribers, the error is still there. If changing the read encoding (in WLMail or the browser if you elect to read the passage online) doesn't make any difference, the error is permanent and you'll have to live with it. It's not WLMail's fault.
Noel