Yeah, I don't think that would cause any permanent damage. Honestly, it just seems like your home button or wake button is flaky and that's preventing you from getting into DFU mode. Be sure you do the little things like turning it off completely and then attempting again ( and again and again). I really don't think there's anything irreparably done, it's just going to be annoying to keep trying over and over again until you finally get it into DFU mode.
If your home button truly is shot (mine was on my iPhone 4, a common problem with that model), then I'm not immediately sure about how to get into DFU mode. But there has to be a way.