The near 10% purchase of DB, which is around 90million shares...

The near 10% purchase of DB, which is around 90million shares would have divided by enough separate holdings to get at least the required percentage of share holders (the ones they created and the ones they knew would vote Yes), making them certain of the Yes vote.
Of the ones they did not know, there was still an amount of holdings which must have voted Yes as well, hence the majority in the result.
It is easy, when you know the amount of share holdings (read votes) to etsablish a majority.