All of the horrific, unspeakable things the Catholic Church is responsible for and/or has turned a blind eye to, and you're concerned about this? Really?
I think the point being made is that is emblematic of all the horrific unspeakable things the Catholic Church has been responsible for.
All hellfire and brimstone about sex/ babies before marriage, adulterers, divorce ... but in fact if you are cunning there are ways round most things that enable you to get away with it.
A former school friend who is a Catholic priest (and raging Tory incidentally) explained "the rules". All legal marriages are recognised by the Catholic Church but only "sacramental" ones are spiritually relevant (ie would prevent you marrying in Catholic Church subsequently when the former spouse is still living).
A sacramental marriage is where two baptised people marry. But if at least one is a baptised Catholic there are extra rules to create a sacramental marriage. If the Catholic is marrying a non Catholic they need to obtain special permission from the Church. And/or if two Catholics are marrying but not in the Catholic Church, similar permission is required.
If the criteria are not satisfied the couple has a mere "natural" marriage which can be legally dissolved without any impediment to a further Catholic sacramental marriage.
Boris is (surprisingly) a baptised, albeit non practising, Catholic. His first marriage was to a Scottish (so I am assuming but willing to be corrected, protestant) woman who married him in the Chapel of her ancestral home (I assume again protestant). With no permission sought = no sacramental marriage.
Second marriage, civil ceremony and to a non Catholic = no sacramental marriage.
So Boris is both Catholic and sacramentally free. Carrie is also Catholic and never previously married. So (astonishingly) is quite right and proper to marry in the Catholic Church.
He didn't even need an annulment. Though in the Catholic Church annulments seem easier to obtain than you would think. One of the criteria is that one of the previously married parties "did not intend at the time of that marriage to be faithful or for the marriage to be a permanent arrangement ".
Gobsmacked.