When he is losing, sometimes he sorts of "give up". He starts going for big shots, aggressive tennis and his opponents most of the time get scared. They get used to reserved, safe, patient Djokovic, and all of sudden when they are about to beat him, balls are coming back more often and with more pace. Fear kicks and boom they lose.
yes it's surely surprising for opponents and helps for the efficiency of that "method".
But I wouldn't call the "other Djokovic" safer than the "adrenalin one", rather the opposite, that's when he makes most loose errors.