This isn't a very intelligent move on his part.
Because Harry has a documented history of stupid racist shit, he's previously tried to address this by saying he's learning from his mistakes and showing contrition. Well, the ones he's not sweeping under the carpet anyway. In this particular instance, he's already said he met with the Cheif Rabbi and Holocaust survivors, learned a lot, humbled etc. That was the PR angle: owning it, doing the work and becoming better.
Which means that even if the accusation is true, he'd have done better not to come out with it now. It just looks like he's trying to deflect responsibility elsewhere.