It may have been unjust regards your relative. Neither you nor I know all the facts, and the party most knowledgeable accepted the dictat of the priest. Q.E.D.
Regards you, no question you did the right thing in NOT going to the Communion rail. Had you, what do you think would have happened?
“Had you, what do you think would have happened?”
I know how difficult this may be for you to understand but I would have done in the belief that I was right before God based upon my own heart before God.