Do you have a source for that? It sounds like more of a mocking thing than actual confusion, but I'd love to see a primary source.
My source is "God's Name ό "Ων (Exod 3:14) as a Source of Accusing Jews of Onolatry"
Jan M. Kozlowski
Institute of Classical Studies, University of Warsaw, Warsaw, Poland
He says, inter alia:
"When it comes to asking for a name, the one who asks expects a priori to
hear a proper name rather than an abstract grammatical form. For an ear not
necessarily familiar with the philosophical tradition identifying God with existence
itself, the naked participle ών, did not say a lot It must haw been rather
perceived as an indeclinable of non-Greek origin, phonetically overlapping
with the Hebrew name of the town of Heliopolis—Ων.
Among the ancient users of the Greek language, we observe the tendency
to Hellenize (εξελληνίζω) non-Greek masculine names ending in a consonant
by appending the inflectional suffix -ος. This can be observed in the instance
of Jewish names that functioned in two versions, e.g., Αδαμ/Αδαμος; Ιακώβ/
'Ιάκωβος; Αβελ/Αβελος; as well as in the case of such Hellenized Egyptian
names as: 4'αμμήτιχος, ΙΙετεσοΰχος or Κόλλουθος. The same is true of the name
of the Egyptian god Ώρος (from Egypt, Ώr). It is therefore probable that non-
Jews hearing the name ό "Ων for the first time declined it many a time as
ό "Ων-ος.
.
.
However, a connection of the hypothetical ό "Ων-ος with ό ὄνος could have
had a more "mechanical" cause. Already in the Attic inscriptions from the
third century BCE we observe an interchange of ω for o. This interchange also
appears in Egyptian papyri, rarely in the third century BCE, but very frequently
from the beginning of the second century BCE onward. Hence, it is plausible
that ό "Ων-ος could be heard as similar to ό ὄνος.
Even a single case of the interpretation of ό "Ων as ό ὄνος would have been
enough to form a meme, which was then transmitted from mouth to mouth.
The rest, in view of die mysteiy that surrounded the name of God of Israel, as
well as of an association of Him with Seth-Typhon and the universal tendency
of the human mind to confabulate, was filled in by imagination."