I think the real reason is they have no idea what sixteenth-century Scottish Buggish lawmen wore, but it’s cool, Mr Bugg.

Transcript:

Mr Bugg is wearing a ten-gallon hat and a gunbelt, waving his arms in an attempt to get Mrs Bugg to stop. Mrs Bugg, on a rearing horse and also wearing a probably-anachronistic gunbelt, waves gleefully as she makes good her escape.

The text reads: “Maybee 2, 1568: Mary, Queen of Buggs, escapes from Loch Buggven castle. Yes, this jail break did not happen in the old west of buggland, but Mrs Bugg really wanted to wear this outfit.”