Happens all the time. Christians or any religious adherent will use agnostic arguments to defend religious tenets.
Intelligent design is often equated with creationism. They are not the same, not even close. ID has no connection to the Genesis account of creation, it doesn't invoke the supernatural, and it isn't anti-evolution. ID is not an interventionist theory. ID has no doctrine of creation. It's only commitment is that the design in the world be empirically detectable. Intelligent design does not require organisms to emerge suddenly or be specially created from scratch by the intervention of a designing intelligence. What separates intelligent design from naturalistic evolution is not whether organisms evolved or the extent to which they evolved but what was responsible for their evolution. According to Darwinian theory, evolution is a blind, undirected, purposeless process. The issue before us isn't ID versus evolution. It's whether the evolutionary process is devoid of design, goal, or purpose. The ID perspective is that evolution and design can co-exist, things can be designed to evolve, evolution can be designed, evolution can be used by design. There is no reason this perspective can't guide an experimental, inductive approach to the world that can help expand our understanding of biotic reality.
There is no reason why a teleological approach can't run an investigation based on observations, logic, and testing. All it has to do is provide testable hypotheses. A testable ID hypothesis doesn't have to have anything to do with establishing the existence of an intelligent designer. The non-teleological account has become accepted by most scientists not because it has provided any tests to distinguish design from non-design but rather due to it's track record that has established it as a fruitful research paradigm. Likewise, ID doesn't need to discover a way to distinguish design from non-design that's convincing to the critics but can follow the example of the non-teleologists by proving its usefulness in helping us better understand nature. Testable ID hypotheses are hypotheses generated via the design inference that help us better understand biotic reality. ID proponents are not claiming an inference is proof. As one ID theorist puts it: "I'm not trying to 'prove' ID (who can do such a thing?) but instead use the design inference as a predictive source of hypotheses." Let's keep our expectations realistic. ID has no obligation to come up with razzle-dazzle experimental programs. ID need only do what every other research program does, namely, guide research that often seems narrowly focused and even trivial. ID does not have to come up with experiments to prove design. ID need only come up with lots of little experiments that result in enlightenment and steady, gradual progress. And this is being done. Go here to see several testable ID hypotheses: http://www.idthink.net/biot/index.html
Okay, so I ask then, what experiments have been run or theories advanced that have successfully used the knowledge base of ID to predict a mutation in advance of its discovery? If you're not feeling wordy you can write "none" and be done with it.
ID does not have to come up with experiments to prove design. ID need only come up with lots of little experiments that result in enlightenment and steady, gradual progress. And this is being done. Go here to see several testable ID hypotheses: ID does so have to come up with experiments that prove design, or else it will always be question begging. You are quite incorrect that the rest of science doesn't have any experiments that address the big fundamental questions. Try doing some research on that.
Interesting commentary ........ IVE WITNESSED INTELLIGENT DESIGN!! On the the Discovery Channel. Geneticists at the University of Wisconsin are able to grow legs on fly's head on demand, among other things