Actually, no it isn't possible to test for that. You are essentially trying to prove a negative, that something could not have happened.
Even worse, without knowing the history of an object, you don't know what steps were required to produce it, and without knowing the steps, you cannot do a meaningful probability calculation.
No one in science claims that any complex structure poofed into existence in one step, and no one in ID has found a structure that isn't comprised of simpler, functional structures.
But consistent findings of simpler, functional structures isn't evidence against ID either.
I don't see it. If we already know the right answer (say, this insulin-producing bacterium is a product of human design), are you really claiming that science is incapable of detecting that? I seriously doubt it. But if so, how is it possible for science to make any authoritative statement about origins?
Even worse, without knowing the history of an object, you don't know what steps were required to produce it, and without knowing the steps, you cannot do a meaningful probability calculation.
That's an unnecessary constraint that essentially calls for scientists to ignore any knowledge of how things (in general) get made. We need not know the history or manufacturing processes used to create the artifacts found by archaeologists, and yet we are still somehow able to identify things as "made." How? Because we can often recognize the signature of "made things." Moreover, even if we're uncertain about the origin of an object, we can try to discern it by looking for known characteristics of "made things." And thus an archaeologist can label an unremarkable chunk of stone to be "a primitive tool."
No one in science claims that any complex structure poofed into existence in one step, and no one in ID has found a structure that isn't comprised of simpler, functional structures.
An airplane meets this criterion. Are you saying that a "design hypothesis" for the origin of that airplane would be wrong, simply because the airplane is comprised of "simpler, functional structures?"