Processed Limit Orders shows my LIHIC 50,000 short order timestamped as Aug 01, 2009 05:38
Trade History shows that my (non-limit) order to short 1 share of LIHIC was timestamped 08/01/09 05:39
Thus, the situation may be that I was allowed to short 1 share while I already had a limit order to short 50,000 shares pending, rather than the reverse.