The published study concludes that more study is needed to determine what the protective mechanism might be.
Right. More study... I have a guess.
I won't pretend to have any exact research, but last Friday night we saw a guy holding the train door open for his friend using his face. The door closed on his face three times. I'm guessing about 13 pints of protective mechanism were involved with that chivalrous move.
And it's not really fair to include drunk people who leave the hospital alive as part of the data. You know months from now research will show a spike in mortality rates at Taco Bells within walking distance of Emergency Rooms. But more study will be needed to determine why.