Question about All in in the small blind

[dire straights]

I run a bi-weekly tournament, one of my members played in the WSOP this year and came back with a new ruling that I am not sure about.

He says that if you are all in and in the small blind that you can win the entire big blind if you win the hand. So if the blinds are 500/1000, it’s folded around to the small blind he is all in for say 600 total, he can still win the 1000 that’s posted in the big blind because that is a forced bet?

We have never played like this but I told everyone at the game I would research it and try to find something out. Has anyone ever heard of this or does anyway play like this.

Thanks for the help.