The guy is a weirdo. It was probably evident right away. Speaking as a single woman, weirdos are to be avoided. How do we know how he responded to her on the date? If she picked up on stalker tendencies, then perhaps she deemed silence as the safest and best option. I have avoided calls from stalker types. I have learned (through experiences in my life) that it is the interaction they crave, even if it is negative. My mother was horribly stalked for 2 years. Unfortunately, she always engaged. I had a situation that was turning quite ugly, and it was only when I enforced pure radio silence that it eased off.
She owed him nothing. She doesn't need to give him advice or a rundown on why she has made her choice.
I signed up for an online dating forum. So I get messages sometimes. The point of this format is to allow a person to have control over who they choose to speak to. If someone messages me, and I don't like their profile or tone of their message, then I am not required to answer. But they don't all see it that way. I have received some very emotional messages bitching that I had not responded. What? Which of the 40 this week were you? I'm not wasting time and energy on those I don't wish to talk to. Get over it. I'm a sexually liberated, N. American woman!
And I have no trouble finding men to spend time with. I have ended every single relationship except one, and it certainly did not break my heart, he just beat me to the punch. I don't have a lesson to learn. I'm always asked out on the second, third, fourth date---and it is always me that finally says no. I am not sleeping with these people, so Prog, your theory is blown.
The guy went out on one date with a stranger. Perhaps he was hurt that she didn't respond to him after that. Perhaps she sensed something dangerous and chose not to (and clearly, she was right! Women, do not dismiss your spidey senses!).
You can judge her behavior all you like, but you don't know how that date went down. What you DO know is he is not balanced nor is he boyfriend material. She may have just been choosing the safest option for her. Social etiquette does not trump these things. I have used silence when necessary. I give an explanation when appropriate. Every case is different, and we judge each on the best we can.