What do u think? My girlfriend said that she's been dating a guy for about 2 months.?

She asked him to bring her a caramel sundae while she was at work and he said he would but never came and didn't call her until later that night. WHen he called he didn't mention the sundae. She is pissed at him because she says it was a small test to see if she could depend on his word. I say she's overreacting. But what do u guys think? I can see her point that there's a principle behind even the small things but she's gone so far as to say that he's not dependable.