I believe the Envato development team should reconsider offering the possibility of redacting a comment in the 15-minute timeframe after the original post if the author has already replied to the comment in the meantime. No user should have the possibility to redact a comment, even in the 15-minute timeframe, if the author has already replied.
Alternatively – but I can see how this could be a much more complex solution – the whole history of the edits should be accessible.
As you will notice from the following screenshot, I replied to the user 5 minutes after he sent his first comment. Upon receiving my reply, he managed to redact his comment and scratch the parts that I proved wrong, while keeping his rude, negative and disrespectful language. I strongly believe that if a customer decides to use this type of tone in their messages, they should also be responsible for what they decide to write.