R' Dov Bloom wrote:
> Netz would be a non-kosher bird, he-netz hachama would be
> the sunrise, the letter heh would be a crucial part of the
> form of this bird/oops/word. Netz hachama is I believe a
> common misnomer.

It is only a misnomer if the speaker intends to speak Hebrew. But if 
the speaker is speaking Yeshivish or Yiddish, it is perfectly 
acceptable. This is similar to many other terms, such as:

"b'dieved" rather than "b'd'avad"
"yomtovim" rather than "yamim tovim" or "yomim tovim"
"shabbos" with the accent on the first syllable, rather than the last

Akiva Miller