[MagicAcid]

In a recent organic chemistry lab, I attempted to reduce benzil to meso-hydrobenzoin with sodium borohydride and eventually water (a rather simple undergrad lab).  I understand most of the chemistry behind the reaction, but I find myself wondering why the meso form of hydrobenzoin predominates.  I believe the formation of the first asymmetric center affects the production of the second, but I cannot seem to come up with a mechanism that explains the results.  According to some sources, there is a cyclic borate ester intermediate during the reaction, but I do not understand how that intermediate actually forms.  Any help at all would be greatly appreciated.

[azmanam]

my guess is this is probably a chelation controlled reduction (as opposed to felkin-ahn selectivity), but I didn't draw out the model

start here:
http://www.cem.msu.edu/~reusch/VirtTxtJml/sterslct.htm#top3