I think the fact that Pakistan Navy on its website has no mention is highly significant.  usually when people dont want to talk about something it means they have something to hide.  the war definitely happened and Ghazi definitely sank.  in the absence of an official Pakistani explanation we have to rely more on official Indian version since Indians are the only ones that did investigate this and examined the hull.  rest all is speculation. keep in mind that Indians could have easily suppresed the info that an internal explosion happened and just said that the hull sustained a direct hit from Rajputs depth charges.