These two unnamed men were hunters in an alternate timeline created by God.
Overview[]
When God showed Sam Winchester another timeline that would occur if he was trapped, Sam foresaw the events.
In the other reality, Sam and Dean Winchester had been turned into vampires and were hunted down by Bobby Singer, Jody Mills and two male hunters. When the four hunters located their former allies, the two men were attacked by the Winchesters with one being thrown out of the window to his death and the other having his throat slit after being stabbed by Sam.
The incident was then wiped from existence after Sam chose not to seal God away.