Yes, it was my son that had a huge vocabulary of words, including clock, uh oh broken, and 6 Cantonese words before he said mummy!
Daddy was his 2nd word.
We don't know why, as he heard us say it all the time.
It became quite funny after a while.
Don't worry, my son is now 2 and sometimes I wish he would stop saying mummy, mummy, mummy!