Any Pokemon that gets any EXP from a battle gets the base number of EV's.

Pokemon #1 = battling a Bidoof (1 hp ev)

Pokemon #2 = Exp share (1hp ev)

Pokemon #3 = Exp share (1hp ev)

Pokemon #4 = Exp share (1hp ev)

Pokemon #5 = Exp share (1hp ev)

Pokemon #6 = Exp share (1hp ev)

this is one of the most extreme circumstances and it still works.