It is proper to call him out on it. And he likely had no knowledge of the attendance list of invitees (I'm assuming that to sit up there you must be invited). So some junior staffer who was still in high school ten years ago and never heard of Foley probably just saw "Republican ex-congressman" and OK'd him. Said staffer will now get admonished to google search history on invitees or requestors.
Oh, and it shows “tolerance”!
And that’s all! Not a big deal...until you begin to make it one. Too many around here throw their chests out over every thing. Pick you shots. You support a candidate...a human being. When snafus pop up, own them and move on (and BTW, this could actually be used to advantage).