Charles may have visited the shop and perhaps even accepted a gift, but this does not make Sam "his tailor." The king's civilian suits are made by Andrson & Sheppard (for decades now), and his military garb by Gieves & Hawkes. You can tell bc he wears a drape cut. π§΅
I think I remember them having a photo of king Charles in the shop, isn't it one of the semi-official stops visiting dignitaries make in Hong Kong?