ergophobe - 9:27 pm on Jan 30, 2013 (gmt 0)
Just recently I have looked a few sites that were doing poor canonicalization at the server level (accessible by www/non-www), but with a site: and site:www search, all the results came up only for their intended domain if
1. They were consistent with their internal links
2. They had verified their canonical domain in GWT
Since they won't show up in the SERPS for their non-canonical domain (even though it's accessible), I would assume that Google can also sort out the author issues.
Of course in cases where they've done nothing to canonicalize their URLs and aren't even consistent in their internal use, it's all over the board with URLs split in the SERPs and dupe content issues that would probably also play into the author scenario you're thinking of.