AITA for snoozing a stranger’s phone alarm

I (27f) was at a “dinner and a show” theater with my family and friends this past Christmas. I had invited everyone to come, as I had the opportunity to work on some of the costumes for the show that night. We were sat at a big table by the stage. The seating for the theater is all tables and chairs, and there are three levels of floor space for the tables that descend as you get closer to the stage. I was sitting at the back of our table, so my head was level with the table on the level above us. The food is served buffet style, and the play starts after dessert has begun.

As we were starting to eat our food, an alarm started to go off next to my ear. The couple that was sitting at the table above me was away getting their food. I waited for about two minutes, but it was LOUD, and positioned so that it was blaring at me. I saw that the phone was an iPhone, and so I tapped the little snooze button so that the alarm would stop, but I (and everyone around us) wouldn’t have to keep hearing the alarm. I planned on telling the couple what happened as soon as they returned with their food, as I assumed it was most likely a medication reminder.

When I did this, my mom, who was at the other end of the table, was astonished and scolded me harshly for touching someone else’s possession. I tried to say that I only snoozed it, and that it had been blaring in my ear, but she told me that it’s never acceptable to handle something that I know belongs to someone else. She said, “what if that alarm was for an important medication?” I replied, “I only snoozed it, and I am going to let them know as soon as they return.” She continued to scold me in front of my friends and future SIL for “my behavior”.

When the people returned, I told them what I had done, politely apologizing for snoozing the alarm, and they thanked me and apologized as well for leaving the phone on the table. They didn’t seem upset at all that I touched the phone.

This incident has come up a few times in conversation since. My mom will not back down or apologize to me for scolding me and embarrassing me in front of my friends and family. Most people that I have told are on my side, but some agree with my mom that it’s never appropriate to touch someone else’s property without permission. I really feel that because the phone was causing a significant disturbance to me it was ok to snooze the alarm, but maybe I’m wrong? So, AITA?