On a separate discussion page, someone stated that "sandwicher" and "sandwiches" are both correct.
According to Den Danske Ordborg, if I'm reading the page correctly:
- en sandwich [ˈsanˌwidɕ] - a sandwich
- sandwichen - the sandwich
- sandwiches - sandwiches
- sandwichene - the sandwiches
Loanword, forms the plural as in English (explained in the notes for the lesson). Same for chip/chips, for example
I have re-listened it several times - she says "han spiser sandwich" - and neither "han spiser sandwicher" nor "han spiser sandwiches".
I'm danish and you're 98% correct, you could make an argument that the voice is making a ch-s sound in the end, but it's a very bad audio example.