The bReak up

My friends boyfriend recently broke up with her. I personally think the kid totally over reacted. Here is the situation...
One day we were all hanging out and someone who has the same phone as my friend Suzy picked up her phone thinking it was his. Well that was the crash and burn of her relationship. The kid who picked up her phone was her boyfriends friend so he just gave the phone to him to give it back to Suzy. So the boyfriend took it amongst himself to search her phone for evidence of her cheating. Even though he wasn't suspicious he went through everything. It turned out she still had an ex's phone number in her phone. Well that just set him off. He started calling everyone of her friends, including me, to see if we knew about this. And he even called her mother to say goodbye and to thank her for everything she has done for him. This was a little o.d. Just because she had the number doesn't mean she was cheating. It turns out she actually HATES her ex and her boyfriend at the time, knew this. Well they now have been broken up for about two months, and he can't even be her friend. She is completely devastated and feels she is wrong. I personally he just over reacted and is just insecure.