That's exactly my take, in the heat of battle after just being involved in a red card / dive incident he thought he heard monkey chants ... let's face it he is not changing his story, nor are the media ... however Spurs as the accused party should come out and refute the allegations against their supporters ... as I said that's not calling Rudiger a liar, simply pointing out that he was wrong.
If this was you or I making serious nationally covered allegations we would almost certainly be forced to withdraw them and apologise or risk being sued, in fact under employment legislation false allegations of racism are dismissible offences, withdraw the accusation or face the sack. We all know that won't happen because Rudiger is a millionaire footballer, frankly that's a shame.