Reply To: If all of Halacha was Given at Mt. Sinai,

See first perek of avos. something like this, please correct me if i’m wrong.

All the time there were neviim, there was no machlokes in halocha. Afterwards, when talmidim became weaker and the transmission of torah shebaal peh became weaker, differences began to appear in halochos, the way they were transmitted to different talmidim, and further on. Hence the appearance of machlokes in halocho.