Cells orphaned from update precedence tree - test condition?

Ran into a strange problem where a user somehow managed to disconnect some
cells from the precedence tree - the cells still had correct formulas but
weren't updating. Selecting each cell, then placing the cursor in the
formula edit box and <enter>ing restored them to life. Subsequently
discovered that Shift-Ctrl-Alt-F9 (forces workbook precedence tree to be
rebuilt; corresponds to Application.CalculationFull) also restored the
cells to life.

Question: is there an illogical cell condition that can be tested for via
VBA that will indicate this type of corruption, perhaps something like that
a cell has a formula defined but no precedent identified? Perusal of the
cell properties suggests some possible candidates, but thought I'd ask here
before experimenting further.

Thanks,
George