Of course, this translation issue wasn't Däniken's fault. What was his fault, however, was his decision to accept Apollonius' poem, written in the third century BCE, as the "official" version of the Greek myth, without understanding or considering the broader context--that Apollonius' Argonautica was one of three ancient poems of that name (the Argonautica of Valerius Flaccus and that of Orpheus being the other two) as well as three extant ancient prose versions (of Diodorus Siculus, Apollodorus, and Hyginus), one major ode (Pindar's Pythian 4), and numerous allusions, references, and other discussions--none of which agree on the details. Apollonius understood this, too, since he tried to pull together divergent traditions by cramming as many of them as possible into his poem, reworking some to make the pieces fit.
Blindly accepting as definitive one ancient text--which was neither the oldest (Pindar's) nor the youngest (the Orphic Argonautica)--underscores the poverty of research and the shallowness of thinking in so many ancient astronaut claims. Just because the modern word "astronaut" was inspired by the Greek Argonauts hardly qualifies Apollonius' self-consciously literary poem as a testament of the alien gods.
So, of course, here is where I put in a plug for my translation of the Orphic Argonautica, which includes a full introduction explaining the many traditions about the Argonauts, explanatory notes to place the poem in its Greek poetic and religious context, and translations of other versions of the myth from late Antiquity and the early Middle Ages.