I was born and raised in AZ but the majority of that time was on the Navajo reservation. Although it was never really discussed because we generally couldn't afford handguns anyway, I always had the impression that nobody ever carried, open or concealed. I'm a knowledge vacuum for that one.
In 1992, as an adult, I moved to Mesa from CA for only a year. During that time, it was very clear that no concealed carry was allowed without a permit. Open carry was fine.
I happen to have a 1992 copy of The Arizona Gun Owner's Guide by Alan Korwin. It says on page 24 that carrying a weapon concealed is a class 1 misdemeanor. On the very next page, it says that no concealed weapons permits are available for "regular citizens of Arizona."
As far as I know, those rules still applied in June, 1993 when I left Arizona to move back to CA.
So yes, you could go to jail for carrying concealed but probably not to prison although frankly, with a good attorney, you may have been able to just pay a fine, give up your firearm and walk with a minor conviction at the time.
Let your "someone" know that he or she was correct!