Are you missing the other arm of the 'or'? Try the following, which assumes 'except' returns null if the second parameter equals the first.

  (or someone
      (except 'Apple some-company))

As a general style, although somewhat inverted, I prefer 'tailing syntax':

  (or
    (except someone 'pg 'rtm '_sh)
    (except some-company 'Apple 'Weyland-Yutani))