Slitherine

A french unit charges 2 russian units. Both units will be hit at the same time. One of the russian units being wavering fails it's test and breaks. The other russian units testing for the broken unit, fails and becomes wavering . Should it test once more for being wavering and being charged ?

I would say no because it wasn't wavering when the charge was declared.

I agree, at the time of the test for being charged it was not wavering. The test for seeing friends break comes later and is an entirely different situation.
Rather bad luck but have been there myself often before.