Buried in an interesting post on Travis Taijeron and other minor league notes (including Bobby Scales' return to Japan) is the first mention I've seen of the source of Zach Lutz's broken hamate bone. It says he broke it "swinging in a cage pregame." There's nothing in the article to suggest that he was hit by anything.
Assuming that this was a non-contact injury, I think it's at the point where we need to resign ourselves to the fact that while some of his prior injuries (e.g. HBPs) may have been simply bad luck, an injury like this (as well as Lutz's history of previous stress fractures) suggests that Lutz is, unfortunately, prone to injuries that will likely prevent him from ever being a regular major leaguer. Which is too bad, since he can clearly hit.