personally, I think a big part of the controversy here is that dan's "warnings" didnt exist, or at least werent obvious. Had it been obvious that dan was yelling 'watch the back of the head!' or something along those lines, I dont think any DQ would have been questioned. However, since from what I saw watching that fight, is dan let the whole thing happen (from about a foot away I might add), stepped in and stopped the fight, then seemed to change his mind and rule the fight a DQ.
If dan didnt adequately warn alessio(sp), the contest should be ruled a NC. If he did in fact issue the warnings he claimed, then a DQ is the right call.