To quote my favourite frost based Disney 'sister's are better than men' heroine. Let it go. It doesn't pay to feel anything too much about differences of opinion. You've both stated your case excellently and that's all that can be asked of you. Your feelings, which might be overwhelmingly noisy, just need to be gently thanked for their presence and placed back in their little limbic system box.

It's likely a vestige of bathing in a milieu where disagreement and dislike occupy the same function. Your limbic system thinks you were either threatened or were too threatening and now has regrets. But there's really no need. You did great and so did Lisa and there's no need to worry further or feel anything. The argument is compelling and the discussion interesting - that's all that matters.

I've been arguing with people on this site since the Penguin was born, including yourself at various points - and I'm still here and still vaguely likeable (for the most part) - don't second guess the importance of telling people what you believe to be true. It's a very good way to build self-esteem. :o)