I was about to propose the same thing having just done this myself twice in a row.
Blame me for being clumsy, etc, but while it sounds trivial, when it does happen you have to:
- Be redirected and wait for chat to load
- Close it all down
- Get back to the question and remove the comment linking to chat
As this tends to happen in "quick fire" comments, the other person likely sees the chat comment while you are being sent to chat and having to close it down. So they think you want chat, and might even have already clicked the link.
It's not a very frequent issue, but I would imagine the code to make it happen can't be too much work?
RobW's suggestion sounds great, but I don't use "UserScript/GreaseMonkey/Chrome extension", and this is not something implemented into the site.
Using the site I don't really want to have to use 3rd party plugins for a better UX (within reason, of course).