Not sure if it would apply in this case, but a rule of thumb in a situation like this is to consider that you have made an erroneous assumption and are looking in the wrong place. There have been certain losses in the "infamous" Bermuda triangle which actually turned out to be lost somewhere else entirely... searchers had jumped to conclusions about what happened.
This applies to many areas of analysis... step way back, forget everything you 'know' and start over.
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-- FORTRAN manual for Xerox Computers --