Under normal circumstances, blowing a tweeter just should not happen. Normally, they get blown by excessive power. In this case, I would guess that whatever non standard hookup your friend had caused a lot of high frequency oscillation that exceeded the tweeters design limitations, which would quickly fry the coils. The point here is, under NORMAL operating circumstances, any well designed amp's protection circuit should prevent blown drivers.
Having said that, if you still desire to fuse the tweeter, my recommendation would be to contact the speaker manufacture's customer service and discuss the matter with them. They would be best poised to advise you on the viability of such a request.