Max,
The phrasal verb "turn out" actually has about 10 different meanings.
Among them are these two similar but subtley different meanings.
1) to prove to be as a result, or in the end...without the idea of becoming
-This form usually adds "to be" or another infinitive and a complement.
ex.
I thought you were evil, but you turned out to be a nice man.
He said he was poor, but turned out to have $500,000 in his bank account.
The sum of 5-5 + (-10) + 1/0 + 2-(1/4 x 8) turns out to be 0.
2) to come to be, to become ultimately
-This form is without "to be", but with a complement.
ex.
How can a boy from a good family turn out a criminal?
Natalya has turned out an absolute beauty!
After many years of study, he turned out an excellent actor.
Sometimes in context they can have the same meaning.
The Olympics turned out to be a disaster for the Russian Hockey Team.....proved to be a disaster
The Olympics turned out a disaster for the Russian Hockey Team.......eventually became and so proved to be a disaster
reference source OED