I did not understand clearly what is your problem, but you may need a function like:
IsTestPassed &= isEqual;
This way, whenever your isEqual function returns false, this will set IsTestPassed to false.
I.e., the only way for IsTestPassed to be true is that every isEqual call has returned true.
[edit]I forgot to mention that this will only work if you initialize your IsTestPassed variable to true.[/edit]