On: Mathematics and Magic: The de Bruijn Card Trick (2...

[tromp]

I can't find your quote in the article. Instead I find

> pass round the cards allowing the audience to cut the deck, thus not altering the cyclic order.

which makes sense. Cutting is fine, shuffling is not.

[amluto → tromp]

That sentence is vague. The author means that first each person cuts and then, with no further cutting, each person takes a card. If an extra cut occurs between the takings of cards, the truck fails.