The only way he could refuse to give communion to the parishioner is he knows for certain that the person is a known heretic, apostate, not in communion with the Catholic Church, or it would cause a grave scandal in doing so.
It does happen once in a great while and it is a very sad event when it does.
So receiving the Eucharist by anyone attending, is pretty much the norm and probably won’t/can’t change. I wouldn’t be too upset about it, as I’m sure God knows what is going on.