It's definitely confusing and frustrating for me. I feel that, if I get an email about a bug I've reported, I ought to read it and respond. And if someone declares it invalid for what seem like wrong reasons, I will raise my concerns about the bug reporting system. If the system is sending both of us emails about the others' responses, then the system is wasting both of our time and adding to any anger/frustration/feeling insulted. Allowing users to edit and delete posts might help. Allowing users a couple hours before anyone gets an email notification might help users to find a better way to put things. I don't know how much of a programming challenge those might pose. Moving bugs to need info instead of resolved invalid might help, when they aren't resolved.
I think we just have to work on being more understanding and polite. Regarding other practices, they can be discussed with the QA team on IRC or the mailing list: https://wiki.documentfoundation.org/QA/GetInvolved#Contact It would be great to improve Bugzilla user experience, but for that we would need more coders to the QA team as everyone is too busy dealing with the incoming user reports. I am closing this report.