With that in mind, you can see the mindset the pro-Fellay, pro-Rome faction would have to be in, in order to deny the Sacraments to a pro-Lefebvre, faithful Catholic.
They would pretty much have to be suggesting that the person is in mortal sin -- but what mortal sin? And what mortal sin are they doing publicly? Opposing Bishop Fellay and a few other SSPX superiors -- in a pious union.
Apparently that's good enough for Schism (which is indeed a grave mortal sin).
Because, for the pro-Rome, pro-sellout faction, +Fellay is the pope (?)
Ridiculous, I know, but the facts are crystal clear: cutting oneself off from, or opposing the Superior General of a pious union does not constitute Schism.
But because it would make it obvious that they held such a ridiculous position (that opposing +Fellay is schism -- which I hope they don't truly hold!), they would rather stay on the safe side of the law and just make your life a living hell and get you to quit. That has been their modus operandi to date.