As mentioned in the previous post, a Trustee sale will be recorded and usually can be seen on the counter recorder's web-site.
You may want to contact an attorney that specializes in HOA issues - below are the web-sites of two attorney firms:
Please call me if you have questions.
Yes, past due HOA fees or property taxes can initiate a foreclosure. If it is property taxes, I believe you have four years to catch up. If HOA, it could be just a few months. Notice of any default would be mailed to the home owner and notice of default posted at the property. There should have been more than adequate notice if there is a pending foreclosure. Notice should include trustee information. Trustee should be contacted before any sale to find out how to cure the default.
Since the sales are public record, any notice would also be recorded in public record http://recorder.maricopa.gov/ . Contact me and I will have a look to see if I can find and sale information for you.
Also recommend contacting a real estate attorney immediately to find out your options.