The problem with crediting universal constants to a deity is simple. We are the result of those constants, I believe both sides can agree on this. However the creationist believes that the constants can be variable, but were set this way by their god. The scientists believes that the constants are constant due to that's what we observe, although some break down under certain scenarios. However the scientist can still defend his position with something like this.
If the constants were different, then the universe itself would be different. Galaxies, solar systems, planets, etc would all develope, or not develope in different ways. Life may, or may not develope, in a different form using different molecules to play by these new rules. However this is all speculation since we have no proof that these constants can be manipulated on such a grand scale, wether it be by nature, man, or a god(s).
So the only way for the creationist to verify his claim that the universal constants can be altered by his deity is well, for his deity to alter those constants. Until then the scientist is perfectly within logic to say that we are the result of those constants, just as evolution is the result of the enviroment.