it's not dishonest if you didn't know that overclocking SHOULD void the warranty. also, intel didn't ask him about it and had the cpu in their possession for testing for several days before sending him a replacement. they didn't even ask him if he had overclocked it. If they had asked him and he lied about it, then sure it's dishonest.
it seems highly likely that intel didn't ask him about it because they wanted to look at the part and see why it failed. If the part failed because he tried to overclock it then they would have told him sorry, you overclocked it and it failed. However, he obviously had a defective part, which their tests showed, so they replaced it.
edit: btw, I think that the correct procedure for somebody who is knowledgeable about these things is to call intel/amd, tell them what exactly you did, what your oc was, etc, and see what they say. if they tell you "send it in and we'll test it", then they determine that it wasn't your fault that it failed, shouldn't they still be able to rma it (at their own discretion of course)?