John Wells’ blog has been talking about the mispronunciation of ‘chorizo’ in a TV advert, in which the ‘z’ is pronounced /ts/, as if this were an Italian (or maybe German) word rather than either /θ/ or /s/, depending on the variety of Spanish the speaker uses.
There are at least two other cases of orthographic ‘z’ being misinterpreted by English speakers. One is standard, the other rather more doubtfully acceptable. Both are Greek prefixes: schizo-, almost invariably pronounced /’skıtsou/ and piezo-, frequently heard as /’pi:tsou/, although “correctly” it ought to be /paı’i:zou/. All the current pronouncing dictionaries give many versions of the second of these, but the Oxford BBC Guide, as usual more prescriptive, allows only the pseudo-Greek version, not mentioning any of the hybrid German/Greek/English interpretations.