Emotionally mature men, please read and give your opinion.?

I went out on a date with a girl I met online, I'm 23 so I know the basic courtesies. After that I didn't feel a connection so we went our separate ways, for a few months, allowing each other to date other people. I got another message from her asking if we could meet up again. I wasn't having much luck on the dating scene so I said yes and we started to set up a time and date. A few days later she decided to go shopping at my work, it was raining out, and I do work outside, so it wasn't one of my better days. Later that day when I went online, I found a message from her, accusing me of being rude. Granted I wasn't in the greatest of moods, but she should be a bit more considerate of her criticism, considering I was tired, wet, and deep in thought, so I wasn't all smiles. Than again I never am. I'm a serious guy. I don't know if she expects me to be something I'm not but, I wanted to know if you think I should explain the situation and apologize? Even though in my opinion, I did nothing wrong. I went to work to work not chat with friends. Or should I offer a slight explanation and try to find someone more understanding?