There are no private messages on HN. This, and your comments in the last 3 months look (AI) generated, which is prohibited in the guidelines[0] but also loathed by the community. Can only speculate, though.

https://news.ycombinator.com/newsguidelines.html

Dave is a brave chap, and posts his personal phone number in his profile. You might be able to contact him that way, but, personally, I wouldn't. I don't think it's really appropriate. I'd say that your comment is sufficient, and not inflammatory.

But I do agree, the comment smells "AIsh." It may not be, however, if this is his standard writing style. I have been accused of being a "bot," for stuff I wrote ten years ago. It's my observation, that people tend to accuse any lengthy comments of being LLM-generated.