If someone goes to that much trouble to explain a bug, I generally expect the developer to file it. It is really a let down when someone has gone to that much trouble and is asked to do more work.
The problem is the developer might want to get feedback from the user (eg: some bugs can't be reproduced). If the developer just copy & paste into the bugtracker then he/she will have a hard time communicating with the user.
Then you should reply with the bug ID and a URL to the bug that you filed and then the reporter can add themselves if they feel like they want to keep track of it.
