If I was wanting to support someone who is in an elected position to represent me, I would NOT want the friend's aunt to be that person. The idea of throwing my support behind someone whose only approach to a problem is to 1)Yell at someone or 2) Never mention it ever (except to all her friends) sounds dreadful.
I would want to support someone who has problem solving skills, diplomacy and a backbone. The person I would support would (in the aunt's position).
1) Check the by-laws to see what the procedure is for determining the replacement.
2) Calmly and cheerfully meet with the committee and point out any discrepencies. This would not involve yelling, but would involve a "Let's do the right thing and I'm still interested in helping on the HOA" approach.
3) Only after attempting open communication with everyone involved would they bring in the rest of the HOA or call for an official revote or whatever is the appropriate measure.
Having a backbone does mean yelling.