I think they meant one of four collections.
Although by all accounts the claim by Tierpark Donnersberg to hold the species is highly doubtful - and it wouldn't be the first time the collection claimed something fairly commonplace was something much more unusual, either. Moreover, the animal/animals in Madrid are almost certainly either Linne's Two-toed Sloth, or hybrid animals containing some Hoffman's blood.
As such, when it comes to definite Hoffman's it is pretty much just Newquay and Skansen-Akvariat.