Can someone help me understand this difficulty in answering another question on Yahoo Answers?

I have been struggling to overcome selfishness lately. I thought that I had made some progress and was excited to help someone by answering a science question here. I wrote out a pretty good answer, but in a few places I was worried about offending the questioner's feelings. I just had the sense that what I was saying would hurt them. I ended up not submitting the answer. I would like help with this.