I did say it is not strictly true, in case you wasn't aware, sly have changed their dishes and also the lnb fitments in the last four months.
So if your friend who has had the quad lnb on here dish for six months, then it's pretty good odds that they are using the old style sly quad lnb.
And sly have done this so that people buying 3rd party dishes cannot use their quads / octos on their systems.
perhaps you would like to tell us all if this new style quad would fit on your friends system.