setting isSpy to false is a very bad idea, since then you spy on a spy and when Jasmine clears the spies at the end of your spec you won’t get the original method.
the method will be equal to the first spy.
if are already spying on a method and you want the original method to be called instead you should call andCallThrough() which will override the first spy behavior.
for example
var spyObj = spyOn(obj,'methodName').andReturn(true);
spyObj.andCallThrough();
you can clear all spies by calling this.removeAllSpies() (this – spec)