Apparently these kind of auto-erotic accidents are more likely to happen
when, as has been reported in Carradine's case, the victim has been heavily drinking that day. In their attempts to get "high" the victims can easily misjudge when applying pressure to their necks.
It's also been reported (from local police and hospital) that there were no other marks on his body, no sign of any breakin, robbery nor struggle, and in fact the hotel door had been locked from the inside.
Video camaras in the hotel lobby also picked up no indication of anything or anyone suspicious.
Sad, but it just looks like the monks at the Shaolin temple never taught young Caine the proper techniques for this type of activity...