2009 Accord - Alarm triggers while key is in Ignition

My girlfriends mother called tonight, and said this has happened to her a few times now. She arrives home, turns key to Off and alarm sounds, (Horn honking, lights flashing, etc. ). No matter what she does, it won't stop, even using any of the buttons on her key fob. So she goes in the house and waits for it to stop after 1-2 minutes. I have zero experience working on Honda cars, but my guess is some sensor is being triggered, or malfunctioning? Although that does not explain why the key remote doesn't shut off the alarm? I though most common OEM alarms could be canceled by using the Unlock or the "Panic" Button on the remote? (I think she even said one time the doors stayed locked, so she couldn't get out of the car until it stopped).
Could it possibly be a problem with her key fob/remote?

Any advice or areas to look or test would be appreciated. :smile: I am 500 miles from her, but I have a nephew there who can check it out for me.
Thanks.