As for Pessina himself, people with a foreign passport who don’t live or work in the UK don’t pay taxes here. That’s self-evidently how it should be, how it has always been and how it will always be.
Pessina, who is Italian-born, has never lived here, so how on Earth could anybody believe that he should be paying his taxes here? It would be laughable were it not so serious. In any case, because Pessina is Monegasque, there is no double taxation treaty between his country and the US, which means that he gets hit by a US withholding tax on all his dividends from Wallgreens Boots Alliance.