Why didn't Snow think that miasma theory could explain the inital cases of John Harnold and Mr. Blenkinsopp in the 1848 cholera outbreak?

ohn Snow inquired about the disease outbreak with the local residents. He found a convincing similarity that the affected people drank water from a particular well. He came to a conclusion that it is spreading through water. Whereas Miasma theory suggested that cholera spreads through air because of the pollutants present. John Snow's argument was that if cholera spreads through air, it would have spread faster than the current affected rate.

According to his assumptions, the well was closed and clean water was supplied and the cholera rate went down in the town.