In other words, ....they try to intimidate there customers into giving up a claim on faulty equipment!! I think they would have a hard time using that little ploy, and i'm pretty sure that their legal departments wouldn't want to push that one either. I bet they have never gone to a legal court of law over chopping a moulded plug top off?? Not unless they can ''Prove'' that the subsequent connection wasn't a sound one. Especially if that connection was made by a qualified electrician.
I know what your saying, but the fact remains, a warranty isn't made void, on chopping off it's moulded plug top!!
I wouldn't hesitate a second on chopping a moulded plug off, if that is what was required, in order to connect the appliance to a circuit in order to use that appliance.