There were two letters printed that were highly critical of Case's article. One was from Fr. Peter Scott and another was from Fr. Ramon Angles. Neither disputed that particular statement by Williamson, and Case did respond, point-by-point, to both letters.
Also, Bill Grossklas, whom I know and greatly respect, informed me that Williamson said the same thing in Oak Park, Ill. at one point.
Just provide the context to the quote and we'll take it from there. Otherwise, it is just hearsay.