This reminds me of that Prince Andrew interview.... Its natural to wonder if there could have been a miscarriage of justice here but rather than create doubt the father's behaviour and words (deluded, minimising, patronising, and entitled spring to mind) imply otherwise. This could have been a great teaching moment for the son.
'We are a tactile family, but he has always been taught that there are boundaries.' 100% proves your son was not predatory...Not! Understands boundaries? His behaviour would suggest otherwise.
'I don’t wish to downplay the importance of #MeToo, Everyone’s Invited and other platforms that, at last, are giving a voice to the genuine harassment that many women and girls endure.' Yet when applied to your son it's hysteria
'all we can do as parents is teach our boys to be very, very careful.' Careful about what? Those dreadful over reacting, wolf crying girls? The biased processes put in place to protect women and girls from men and boys? It would be much better to teach your your son, from an early age that women have boundaries which are centre around what women rather than men or the male perspective.
I hope for the girls, for whom the father and I suspect the son give no F's, it has been empowering and for the other boys as the school a cautionary tale about disrespecting boundaries and male entitlement.