First of all, as a non-native speaker this is very difficult to read (but I think native speakers will have a similar problem). Secondly, its absolutely not clear on what constitutes 'product, any article or service'. Is it a clearly defined part/add-on/component or can it be anything? Basically, does it mean that I can go resoldering all the capacitors on my logic board with others and/or replacing the PSU by something I have built in my kitchen and then insist that my warranty is in effect? In case of the rMBP, Apple clearly states: 'this product does not contain any user-replaceable parts'. Isn't that 'enough' in this case? Now, the Act basically means that you can use any brand of external HDD, usb-stick or other device in combination with your Mac, but I don't see how altering the product (that is, the laptop) itself falls under the definition of the Act.
P.S. In electronics, there is often no way to easily 'prove' what caused the damage or even to identify the failed part, thats why people usually don't even bother.