Sure. But not having access to the tickets database might cripple a team pretty badly.
One reason I'm still toying with the idea of trying fossil[1] "for real" and/or find/make a tool that distributes issues within mercurial/git like
http://www.bugseverywhere.org/
Note-to-self: looks like hattawiki might be a nice companion on the path to "distributed everything":
For a distributed wiki try gollum. It's the wiki engine behind the github wikis and it's basically a wiki where the database is a git repo. I love it for family use. I can put up a nice web interface for everyone else to edit and yet I use git push/pull and my normal text editor. Works great.