28:57 you really were correct that it is really close to a mating net. Since the white king can to to the entire black diagonal consisting of f4, e3, d2, you had to put the bishop on that diagonal and the only real option here is bc1. Also, your rook on e8 needs to keep protecting that e4 pawn which you later blundered by moving the rook. And your other rook needs to block that last remaining square, d4 for the king. So, rc4 now is very threatening since bc1 would be mate without the rook, and even so, they need to give up the rook for the bishop.
On the second game if they had have continued and saved their Bishop you could have played Bxf3 winning the Knight because moving both Bishops would be a discovered check from the e8 Rook.
